New to DAWs, trying to find a controller that will work well with Sonar.

I have Sonar X3 and am shopping for a MIDI controller.  Of course, I'd really like the Nektar Panorama P4 or P6, but I'm sure it's way out of my budget.  I feel 49 keys would be enough for now, and would help keep the price down.  Although I'm not certain about all their features yet, I'd like a controller with the most options for the price.  I feel I'd like semi-weighted keys if possible, since I'm a former piano player.  Some of the ones in my price range are the Alesis VI49, Nektar Impact LX49, Novation Launchkey 49, or M-Audio Oxygen 49.  Based on the reviews I've read, the Oxygen doesn't have very good build quality, and the Launchkey seems great except very oriented toward iPad integration.  All of them appear to be automatically mappable to everything but Sonar (which, for whatever reason, doesn't seem to be the most popular of DAWs on the market). 
 
The only other keyboard I've owned was an old Casio that didn't even have MIDI output, and had a very plastic feel that was not at all like a piano.  I'll probably need to elaborate on my needs, but I'm not certain what they are yet, and I would like your thoughts.
 
Edit: Sorry about the lack of links, but they were removed due to my newness.