kourtney,
I don't know if you are a woodworker but welcome in any case.
There are better forums than this for answering your question in detail but as a Mac user myself, I can start you off.
Any program can be run on a Mac including Linux and Windows stuff using the excellent virtualisation software that now exists. I am currently using Parallels v5 to run a variety of Windows programs. I have also tried a whole host of CAD programs recenly, mostly focussing on Solid modellers like Solidworks, Solid Edge, Alibre, SharkFX, VaCad etc. I have also tried a few game type modellers such as 3DVia, Rhino etc. many of these will do a lot more than just 3D game modelling however.
They all run fine on the Mac in Windows under Parallels and some, like Rhino have Mac native versions either as Beta candidates like Rhino or as full blown programs.
In point of fact, for my needs, I use Sketchup mostly and Kerkythea if I need to render something. Both of these run natively and very well on the Mac.