3ghz+ so pentium 4... amds are better at gaming

yes it is possible to get it less than 1250

gfx card i would recommend getting a nvidia 6600 gt or 6800 (not sure which will fit in ur budget)
processor- amd 3000+ or higher
160gb western digital sata hd
1gb of corsair performance xms pc3200
power supply- antec, thermaltake, enermax, etc
thermal paste
heatsink/fan
mobo not sure if u want sli


go newegg.com, zipzoomfly, tigerdirect to look for parts