too much bro, just build your PC. Build it and then LOVE IT.
Hyper X blue DDr3 Kingston 2GB (2 of em) Matched RAM
3.60GHZ Dual Core Athlon II X2 255 Processor
ATI Radeon HD 5770 grapics card 970mhz
Motherboard ASUS MicroATX
combat arms runs with no lag, but when it comes to Internet and servers and how other people are being connected, yes there can be lag and FPS drops. but everyone is wrong, when they say you can have the best computer but CA will still lag. its not true, the only time you lag with my kinda computer is if its an outside problem. altogether this costs $600 and it competes with computers that are twice its price.