You should all note that while the GeForce FX series peforms quite well on older games such as Quake 3 and in the 3dmark01 benchmarks it did quite well but on any DX9 games it won't perform that great. All the FX series have significant reduction in framerates in DX9, which is exactly why I stay away from them and take a Radeon.
They're not bad, but don't expect to run any DX9 games on higher graphics especially with a higher resolution. Even the FX5950 got killed in 3DMark03...
My recommendation would be a Radeon 9800 PRO if you're going for Far Cry... good luck nevertheless.