FS2002 is actually quite demanding on the processor, or at least the processor/gfx card demands are a little more even than most games which tend to rely heavily on the graphics card.
For what it's worth I've got a Windows XP system - 1.8Ghz Athlon XP paired with an old Geforce2 MX, 512Mb DDR RAM - and FS works fine at 1024x768 in 32bit.
These days upgrading your processor is a lot cheaper than buying a current generation graphics card, though pretty much anything with GeForce on it, or any recent Radeon card should be fine.