I have a sister who uses mac over pc and I have no knowledge in the mac department. I just wanted to make sure that as far as the hardware goes, you can build a computer for mac just like you would a pc, the only difference being installing the mac software instead of windows. If so, is there any limitations mac has on the hardware that windows might not (i.e graphics cards, processors, motherboards etc etc)? the best example i can think of is how much RAM mac can make use of?. like windows and there 32/64 bit systems or vista using up 2gig just for the OS alone.