AMD Athlon 64 3500+
EPoX EP-MF4ULTRA Socket AM2
Geforce 7600 GT
1 gb of RAM (don't know which brand to choose)
Let's be honest with ourselves, $400 isn't enough to put together a decent bare-bones...
$650 will put you in the drivers seat with decent components, the graphics card is ok but you'll never be happy with that Athlon 3500+, you want at least a dual-core 4200.
That motherboard is very inexpensive...you know the old saying about "you get what you pay for" , well that applies here.
1Gig of RAM is fine, you could get away with 512 for now....
Check the classifieds section for some good deals on hardware, I'd like to see you save up a bit more and build a decent system you'll be happy wit instead of a system you were forced to build because you couldn't afford something better...........just my $.02