LOL, first off, this is an RTS. Any FPS at or above 24 FPS is acceptable. You do NOT need 60 FPS to play this game at all. This is not a first person shooter where the higher frame rates make the game smooth enough that you don't have problems lining up shots in fast combat.
This game does not require much to play.
C2D
2GB of ram
4650 video card (or equivalent) is all you really need
Now, if you want to max out a few things you need to upgrade. The game is more CPU intensive than GPU right now since it lacks AA/AF. If you want better graphics and smoother game play then up the CPU to a quad and overclocking will do wonders. If you want to do AA/AF when (and if) it is introduced then you will need a better GPU.