What about one of these :P

3870's cheap and fast - maybe just get yourself a wee bit more ram, 2gb is kinda border line for games now days. 4gb hardly costs a thing. As for the cpu/mb combo. Can't say i'm too much of a fan of the amd chipsets.. as for nforce... well.. same thing... and we won't even start on thermaltake psu's.

c2-duo/quad + intel p35 cheap and stable... w/ a enermax / pc power & cooling psu, but anyways, i digress.