Fallout 3 On An Amd 3700 Best Video Card And CPU For My Needs?

Best video card and CPU for my needs? - fallout 3 on an amd 3700

Looking for a processor and a graphics card upgrade my PC for 3 years. I do not want to buy a new PC and really just want to squeeze one or two years beyond. I'm in the game and want something to me on my games on high settings with a wonderful view, if it can exploit possible. I like (SPF 2 Modern Warfare, Crysis) and role-playing games (Fallout 3).

My glasses --
Windows XP Pro
2 GB DDR RAM
AMD Athlon 3700 + Socket 939
PCIe x16 NVIDIA GeForce 7900GS

My motherboard is a bit old and not only supports Socket 939 Athlon processors (compatible FX or Opteron series also supports dual-core chips and simple, not quad-core). The graphics slot is a PCI Express 16x regularly, and not the new PCIe 2.0.

I want a dual-core processor,I get the most for their money, and a video card that will break my games smoothly at 1440x900 (widescreen) video at decent settings and not the bank.

Suggestions?

PS. I could buy a new motherboard, if it comes, but really just want what I have to work.