I assume Sonar 7 will work with about any soundcard or interface (i.e. not like Protools).
To start out, if you just need a pair of inputs, its hard to go wrong with the MAudio card. For one, I'd buy MAudio (or just about anything) over Creative/Emu. For two,I just saw the 2496 card on zzounds.com for like $85. So even if you decide you need more inputs later, you can add another MAudio card, or scrap that all together and go with something like the Firepod.
I use a 2496 card in my living room computer to play mp3s through my home stereo set up. I use (2) 1010lt cards in my recording computer. I've had nothing but good luck with these guys for the last 7 or 8 years now. Solid hardware and solid drivers.
Again, just my 2c. There's probably a few people out there (or here, even) that really like the emu stuff... but I'm not one of them...