Want to perform the keyboard shortcuts through a separate dedicated pad. Separate number pad don't have enough keys/buttons. 
Not a fan of Faderport. 

Specifically, how do you want the controller to perform.   
 
Some will only perform transport controls
Others will have fader movements and transport.
Some will completely allow you to operate Sonar without you touching the mouse and keyboard screen much.
 
You have to be a bit more specific as to what you want the controller to control, then we can provide recommendations.  
 
Also what is your budget, the more controls to manage, the higher the price tag.
 
This link may help as it is a guide for DAW CONTROLLERS

Jesse G
Specifically, how do you want the controller to perform.   
 
Some will only perform transport controls
Others will have fader movements and transport.
Some will completely allow you to operate Sonar without you touching the mouse and keyboard screen much.
 

 
I don't want transport control or fader movement.. 
I want to: 
- control snap on/off
- loop on/off
- auto punch on/off
- Edit control (Smart, Edit, Select, Mute)
- Nudge 
... things in that nature.. which will make my tracking process and mixing process workflow smoother. Transport would be nice but my budget is only $150. 
Thanks in advance. 
 

Sonar has a list of "Commands", which is more or less the same as the list of shortcuts. There are also complex operations, which do not have direct shortcut. Your list is in the first category, so you can:
1) just use normal keyboard. There are gaming keyboards with extra keys, configurable as arbitrary key combinations. And there are programs which can map normal keys to other, but you can assign commands to arbitrary normal keys and combinations within Sonar.
2) use anything which is visible as MIDI device in Windows (and so in Sonar). The mapping can be done in the same section as for keys or throw ACT ("ACT MIDI" or "Generic Surface"). Also applets for Phones/Tables fall into this category.
3) use anything which is visible as a Game controller/Joystick in Windows (and so in Sonar). Cakewalk has specific ACT plug-in for that or you can use my (in case you find stock plug-in limiting).
 
So virtually any device with buttons can be used for keyboard shortcuts. Only in case you also want control parameters by knobs/encoders/faders you are bound to specialized MIDI controllers.
 
 

Just going to point out that supposedly the new(ish) "Control Module" allows you to map various commands to it's buttons and they in turn can be mapped to be trigger by a MIDI controller.
 
I have not tried any of that yet but I'm pretty sure that's how it works. At that point you could use pretty much any controller. I've been contemplating trying it out with my Korg padKontrol because it can save 16 scenes internally and has 16 pads so I can set up multiple "scenes" just for specific tasks using the Control Module and for Transport stuff.
 
There are also two mappable knobs on it so I can control a couple variable controls as well (two for each scene). It's easy to switch scenes (you just have to hit two buttons to load another scene).
 
The pK is kind of old so it can be picked up for cheap and works well for drum programming (which is what I bought it for). Other units like the Akai ones or the even less expensive NanoPad ones should do similar things.
 
My point is that maybe jury rigging a device like that up might be more flexible as opposed to buying a standard dedicated controller or using a keyboard controller.
 
Just some thoughts.
 
Cheers.

I´m using a HOTKEY MATRIX from DNA music labs for Pro Tools. It´s a fully programmable USB-Keyboard with 144 keys. You can buy these kind of keyboards without pre-programming much cheaper for example from cherry and program it yourself. I plan to reprogram mine for sonar, but I haven´t managed yet.
You can not only program key-strokes but even record a series of mouseclicks for using funktion in menues without dedicated shortcuts.
 
 

maybe take a look at these products:                http://xkeys.com/

If you have a tablet, TouchOSC or Lemur.

+1 for Lemur on a tablet.

I have both Lemur and TouchOSC on iOS. Lemur is more powerful, with MIDI and OSC, but TouchOSC has better support of computer keyboard emulation, so it is more solid for assigning buttons to keyboard shortcuts. Lemur kind of emulates ASCII keypresses too, but it is an usupported legacy feature that I haven't been too lucky with.