Hey that's weird All my images are gone?? I made diagrams of 2 set ups? I couldn't open my Imgur account at work for some reason and I used some other obvious stupid site! I could see them clearly each time I re visited this thread?? OH well. I try again. 
 
There hopefully you can see those. 
I've had trouble posting pictures lately as the copy link thingy doesn't seem to work so I'm right clicking the image now. 

You could use a mixer as Tim has said and possibly a good soltion if you do your own sound from stage. This would require the mixer to have the following features. 
XLR or TRS balanced outputs to FOH mixer
Aux 1 be pre fader  ( almost a standard) 
Headphones cue mix can solo aux 1 ( this is not so common) 
Aux 2 used as an effect loop for your vocal processor. 
 
 
Vocal mike to Channel 1 and aux 2 used to send to your effects. Pan Ch 1 to the Left. Fader at Unity  Aux 1 and 2 up. 
Aux 2 return only to Left side or if return has a pan turned to left
Keyboards to CH 2 and 3 and panned to Right or use stereo channels and only use Right side. Fader at Unity Aux 1 up. 
 
Monitor send from FOH to CH 4 , channel Fader off. Aux 1 up 
Vocals will go to FOH via left main output and Keyboards the right\  
Aux 1 is used to make a mix of Ch 1,2 3 and 4 for your in ears via headphone output. Some boards even allow Aux 2 to send to Aux 1 so you could monitor your effects too. 
 
A board with Sub mixes could also be used.  
Also vocal effects could be done with a board that has inserts on the channels. 
But those 2 features are only found on more expensive mixers so we will leave that be.  
 
 
 

I use a simple mic splitter on Vocal mic.  One feed to a small mixer, one feed to FOH.  That way FOH gets a steady input.  For the Keys you could do something like Line Level Splitters:
http://www.fullcompass.com/prod/525407-Radial-Engineering-LX-2 (Yeah, I know pricey, but it IS Radial).
One feed to FOH, the other to a small analogue mixer. 
Now assuming you do not plan to expand beyond 2 keyboards, you need two mic/line level inputs (One for Vocals, One for "Full band" Monitor feed). Then you would probably want two stereo feeds.
Something like this would work:
https://www.sweetwater.com/store/detail/MG06
 
Then you just Mark Each channel with its purpose Vocals, Monitors, Key1, Key 2.  Take Your IEM and plug it into Phones.  Then you can adjust anything you are doing Vocals, Key1, and Key 2 with the rest of the band monitor and never effect any of the FOH settings.
 
Me, I do it the easy way.  I have the Behringer XR18 digital mixer.  I also use it as my interface. 
I have yet to use it as a true digital mixer, but I did get a Personal Monitor.  So if I went Live I would use this!
https://www.sweetwater.com/store/detail/P16M
One CAT 5 cable and I have full control of ALL 18 channels and do not effect FOH!  Full EQ on each channel too!
 

After reviewing everything, I am going to get a new amp with multiple inputs (probably Behringer Ultratone KDX15) and maybe well my Centerpoint Stereo Spacestation V3. I'm also going to a 1 keyboard setup for my next two rock gigs, tonight and tomorrow--my VR-09 is great for organs and synths, and piano...not so much--but I will suffer it to not have any connection and equipment headaches for the short run.
Thanks to all, in the meantime I will keep pondering the solutions and see if I change my mind again over the weekend. 

Make sure to read reviews before you buy an Amp. My experiance with the Behringer amps is the controls get scratchy in sort order. I just had experiance a few weeks ago with one, IT wasn't very old and it was crapping out becuase of the EQ section. This is the second one I've personally seen. 
A keyboard amp is a great idea as many keyboard players I've worked with use them. 
It not only functions as a sub mixer but is their stage monitor. And many of them use them when they do a solo gig in a coffee shop or lounge. 
The ones I've used without issue were older model Yorkvilles and Rolands. But these day a many of the powered speakers have 3 channel mixers built in too. 
example- https://www.qsc.com/live-sound/products/loudspeakers/powered-loudspeakers/k2-series-new/
 
This is dated but still good info: 
http://www.keyboardmag.co...at-keyboard-amps/29176
 

The number of different ways to set up in-ear monitoring is enormous, and I suspect most people who use it have their personal favourite way of doing things. At least, they do unless they're a singer who doesn't play instruments and only needs to hear their voice and the rest of the band so setting up an in-ear mix is pretty straightforward. After that it gets more complicated the more instruments and other stuff you need to add in to your personal mix. The good news is that once it's set up so it works the way everyone wants it needs little adjusting after that.
 
A couple of final thoughts. In-ear can be very isolating and it's meant to be. So you can lose both audience noise and verbal communication with the rest of the band. The first can be solved by pointing a mic into the audience and blending some of that into the monitor mix, which has the added benefit of making the gig feel like a gig rather than sitting in a studio.
 
The second by either good lip-reading skills, which many musicians have for simple frequently used phrases and working out in advance a communications system that indicates e.g. "last time through" or "about to end".
 
When considering ear-phones watch out for what they and the flexible part that sits in the ear canal are made from. Latex in particular is a bad idea because you can become sensitised to it and from then on have a reaction whenever you encounter it. Good in-ears generally avoid that problem by careful use of materials. However, I bought a cheap pair of Panasonic in-ear buds for general use a couple of years ago and the skin just inside my ears broke out in eczema after using them for a while. And it now also breaks out when I used my Shure in-ears as well, which never caused me any problems before. It is getting better but taking its time about it.

Interesting info on the Behringer amp. Most reviews were very positive about it, but of course real-world use in this forum is a pretty influential source of info. Haven't ordered it yet. I have a small Roland practice amp, 60 watts, and I've never liked it very much, and the larger ones are very heavy and very pricey, and I don't believe they will sound appreciably better than either a comparable Peavy or Behringer keyboard amp. Motion sound is just too pricey for what I need. My CenterPoint Stereo amp is the best-sounding ever and has other advantages, such as small footprint and a miraculous stereo spread of sound from one speaker (with a side-firing speaker built in), but because of it's lack of multiple inputs I would like at least an alternative. Or, I will just continue to either use one keyboard for now (not ideal but not terrible), or use DI boxes and stage monitors and just go into the PA, like at some venues, where it works quite well and is easier for the sound guy to adjust on the fly.

If you bought the Radial Key Largo DI it would serve 2 purposes for you. It would mix 3 keyboards plus option to use a laptop via USB. The Laptop would give you all your Sonar VST's!!  So your fully covered input wise.
Then the Outputs you would be able to send a stereo or mono signal to both the PA and your stage amp/ monitor system. 
It's nice to have control! 
 

 
I totally understand the need for 2 pianos as you need weighted action for piano but synths and organs are totaly imposible on weighted keys. 

The Mackie SRM150 is worth considering as a stage keyboard amp/personal mixer. I know someone who uses one - mostly for piano - and it works pretty well despite not containing a huge speaker. And I'd consider a lightweight PA cab rather than a Behinger combo. Behringer power amps are pretty good, their mixers are pretty good, especially for the price, but my admittedly limited exposure to their instrument combos suggests they aren't the most solidly built  things and can be prone to rattles and buzzes.

the DI box does seem like an interesting and useful possibility. And I have used my iPad on stage (not for the rock band, but for solo or duo work) with backing tracks, in addition to my two keyboards, so as much control as I could have would be wonderful.