I moved to a tenkeyless board, but the DSI Modular Mac has one saving grace: the numpad scancodes can easily be done with Fn-key combinations. (I could also buy a matching numpad module later, if I wished.)
For gaming, though, it had better be a game that doesn't make heavy use of the numpad. ArmA might. Any sort of vehicle simulation WILL. (In fact, they'll use the entire keyboard, tenkeys and all, several times over with the help of Ctrl, Shift, Alt, and combinations thereof.)