They all look fine to me, but the cooling and PSU can be a bit better.
Anyways, for the Graphics, for 200$ you can get a ATI HD 4850. 4870 If you get lucky. 9800gtx is another version of a 8800gtx but slightly better. I think in some the 8800gtx is better.
Gee, guys, I'm blushing here. If you keep posting stuff like that I'm going to start a fan-club and charge membership fees
Why the HD 4850:
1. it's a bit faster than the 9800GTX. Prices are around $160 at newegg right now, while 9800GTX is around $200.
2. adding a second one can be done on a $140 motherboard with an Intel P45 chipset. With the 9800GTX, adding a second one requires an nVidia motherboard, which is typically more expensive and less stable than a P45.
Onboard audio: this is very subjective. It depends on how good your ears and speakers are, on what type of music do you prefer, how loud, whether you listen to lossy compressed files (mp3) or CDs, how much noise you have in your room, etc. Most motherboards these days use Realtek chipsets for audio, so there's really not much difference between one MB or another in that area. You should probably try onboard audio for a while and invest in a sound card only later, if you're not satisfied.