processor .AMD Phenom II X4 965 Black Edition 3.4ghz
gfx ..sapphire 6950 1gb
ram..kingston ddr3 4x1 1333mhz
psu..xfx pro 550w
cabinet..cheap one with good ventilation..
gaming res ..1600x900 at high settings
dont suggest cpu higher than this rate because tight on budget..
Only buy an AM3+ motherboard , preferably with a 970 or 990 series chipset so you can upgrade later .
Consider the FX 4100 rather than the phenom . Its cheaper and overclocks well [ when you change your mind] but till then its performance is comparable
The RAM should be 1.5 volt or less , but dont buy 4 x 1 gig sticks . Get 2 x2 gig , preferably 1600 MHz
You will not need the powere of a 6950 at that resolution . A 6870 or GTX 560 [ not the TI] will play anything on the highest settings
The Antec 300 Illusion is an excellent case and was only $40 when I last looked
are u sure that a gtx 560 will perform best for games like bf3 at 1600x900 and future games after 3-4 years not at that res but some what lower like 1333x768 minimum res with high settings..if i buy a gtx 560 i will invest the remaining money in i5 2400 with an intel board dh67vr(cheap amd most reliable with usb 3) and about ram any h67 board supports only 1333mhz
If you are set on not overclocking and using this comp for gaming only, I would recommend the intel i3 series (2100 or 2120 seem to be the cheaper options). They do better when it comes to games compared to similarly priced AMD cpus.