With all the DAWS available.....

I wouldn't worry too much. While a number of the specific deal will probably never return, deals nearly as good will likely happen this time of year again. I mean Studio One was not much cheaper with the Sonar crossgrade than just getting it from some place like Audiodeluxe on the black Friday sale. The only deal that might be something of a "one time only" is Cubase, it rarely seems to go on sale.
 
However that said you could look at just jumping on a new DAW. I did because I figure while Sonar won't break, I can probably make it run for the next 20 years, I'd rather just start learning something new and getting used to the new workflow.
 
I picked up Cubase, personally, and I quite like it.

It's a tough call.
On one hand, Sonar hasn't stopped working.
On the other, it's prudent to at least investigate the options... knowing that (to remain current) you'll ultimately have to make a move.  (This assumes Cakewalk doesn't get sold/resurrected)
 
There are some great deals available right now.
If you've got the budget, it's not a bad thing to have a couple different options in the toolbox.
 

Mesh,

Keep using Sonar, but, at the very least, start planning ahead.
Reaper will work forever without paying, but you'll have to endure
the Nag screen for 5 seconds.  It's a great way to get your feet
wet learning another DAW without any out of pocket expense until
you're ready to purchase.  And, if you decide it's right for you,
it's only $60!

Now, IF I were you, and I had the funds, I'd take the Samplitude 
Deal currently being offered.  There is just WAY TOO MUCH there
for the price to not take it.  You get

Samplitude Pro X3
Independence Full
Vandal Amp Sim Full - $149 retail
Analog Modeling Suite - $149 retail
24 Virtual Instruments - $39.99 Each
The upgraded True Peak version Limiter
Izotope Mastering Suite
Soudforge Pro 11 - $399 retail
SpectraLayers Pro 4 - $399 retail

And a TON more...and Pro X4 is probably not far off.

IMO, Samplitude is THE most underrated DAW out there.
It's big brother, "Sequoia" is used in many production houses.
And, from what I've read, Magix is currently hiring new developers
for their products.

Now, if you don't want all that, then go the Studio One 3 route,
which gives you alot also, and has an abundance of tutorials,
and Version 4 is apparently not far off.

The bottom line is YOU have to decide what's BEST for YOU!

One thing I know for SURE...there are ALWAYS more sales!!!

(that being said, I don't think this Sampitude Deal will repeat,
 but I've been wrong before)

You can always use Virtual Bass until you can get one also, and
sometimes you end up getting a better deal!!

Also, you can use your guitar to play the bass parts, and convert it to
MIDI to drive a Bass VI.  There's ALWAYS a way!

Mesh ,
 
You play guitar plus you have all the Midi Guitar stuff including Midi Bass right?
 
The more more I think about your situation , the more I think you need to get a Bass
 
If you get a Bass you can put your own playing stamp on all your music . Then you don't have to use all the lame sounding Bass parts that come with 3 rd party loop and sample content ...
Now don't get me wrong some 3rd party Bass stuff sounds good , the thing is you will be able to copy /learn what you like and leave the rest ...VIA Cafeteria Style
 
Also you may have real Blast spending time learning and playing the bass ...
OK , Guitar players line up to the left ...sheeeshhh , that line goes for miles ...
OK bass players line up to the right ...that line is much shorter 
We all know that finding a good bass player and keeping one is hard because bass players are always in demand
 
all the best ,
 
Kenny
 

Yeah it's been a weird process coming to terms with all the possibilities. 
 
Personally, I took advantage of a BF sale and topped my Reason license up to 10, as I was on 7 and a lot has happened up in Sweden in the past couple of years. Not a lot of people seem to talk about it much around here but it's a remarkable product in many ways, very creative and fun and deeper than most seem to realize. 
 
Then I plopped down a whopping $29 for Mixbus, I figured hey, worth a look at that price, see if the magic fairy dust its enthusiasts go on about is something that will work for me. 
 
Then I installed tested a lot of other things. Studio One, Mixcraft, Samplitude... I liked them all in various ways, but none of them was "clicking" for me in the way that others have described above. Studio One was probably closest, but I kind of couldn't quite decide between that and the greater depth (and apparent complexity) of Samplitude. 
 
Oh, and I poked my nose around Live a bit more - I have a license for 9 Suite, which I hardly use at all, long story, I know it's a remarkable program but I somehow can't imagine using it as a main workhorse. 
 
Then I updated and fired up my Reaper demo that I've had installed for years, occasionally kicked the tires a bit but never actually did any work in, and my mind was quite blown. Reaper is *insane*. I think it's as deep as anything out there, deeper than most when you include all the add-ons available, mostly for free... plus, the efficiency and stability of the code is unbelievable, and the pace of development simply breathtaking. And the community seems very cool, on par with this one if a bit nerdier... It didn't take me long to realize that it's the one for me to gradually move towards. License bought, decision made. 
 
So now like Bapu (and a few others around these parts) I have an embarrassmet of riches: SPlat, Reaper, Reason, Live, Mixbus... I think that will be enough for me for the foreseeable future! The sales on S1 and Samp (and Cubase, and DP!) are very tempting but so is not having to explain to my wife why I need 7 (or 8 or 9!) DAWs when I already have 5 perfectly good ones... 
 
So I upgraded my Toneboosters to BusTools3 instead - that'll cover me for some of the Cake plugs that don't port over (Adaptive, couple of others; I never used the Nomad stuff much anyway). I think otherwise I'm pretty covered.