[danshaffer]

for cad on a mac your options are pretty limited... i tend to use sketchup for simple stuff (sketchup.google.com), but for the more complex stuff i switch over to the pc for solidworks (i suppose you could use inventor)
if you're willing to taint your mac with xp or vista, you could run solidworks/inventor/mplab/etc no problem

(you should be able to use Eclipse (eclipse.org) or Xcode (ships with your mac, probably on one of the extra install discs) to write the C code, although I have no idea if IFI loader will run on OS X)