athlon OR Phenom
dual core or quad core? may six core din ata amd
siguro mga 5 - 10k yan
nag upgrade ako from amd sempron to athlon x4 umabot ng 11k nagastos ko
Athlon is a bang for the buck CPU, IMHO, at least 2 cores (AMD Athlon II X2) with 3.0 Ghz, you surely be on gaming. for motherboards, i really don't know what to suggest as I don't have the proper knowledge. The only things I look at for motherboards are memory slots (ddr2 or ddr3), CPU slot (either for AMD or Intel, magkaiba kasi, tapos may iba iba pang slot, example am2 am3 para sa AMD, don't know much for the intel though.), built-in things (sound card, video card).
go to local stores websites (ie: pcx, rsun, pcgilmore) for prices and specs.