Help with choices

i plan on getting a notebook end of year/early next. i'll be going to school for architecture and obviously will use it mainly for that purpose. the challenge is most of the CAD programs i'm aware of are PC. i would MUCH rather have mac for the all the obvious reasons. does anyone know of CAD programs for mac that would work for school pojects(compatibilty, etc.). the main concern is i cant see myself spending the $$$ on a mac if i cant use it for arch. thanx