Not much to advise here but go with Nvidia, Intel, and a 64-bit OS so the RAM can actually be used, not like you need more than 4 gigs of ram anyways...
Pretty simple.
Intel>AMD to Performance
AMD>Intel to price
Nvidia>ATI to performance
ATI>Nvidia to price and in some cases power consumption+space.
If you're willing to sacrifice price for performance go with a Intel,Nvidia mix. If you're willing to sacrifice performance for price then go with a ATI,AMD mix (then you'll probably get to use AMD overdrive but you won't really need that if you don't like touching the clock multipliers of your CPU).