You might be better off with a separate USB numpad. Every time I need to use the numpad I have to move my right hand off the mouse or my left hand off WASD and move it over to the numpad. Having the numpad next to WASD might be a better option.
I've been playing on a mini wireless keyboard that came with my iMac but think I need to go to a full size keyboard for this as I'm missing some of the view keyboard shortcuts, it not having a num-pad.
Are specific gaming keyboards worth the extra money or should I just get a bog standard Microsoft jobbie?