Autodesk Autocad

Iam currently looking for a new laptop. Been using PC all my life, ive really wanna give mac a try. Can anyone help me decide which To get ? 14" Ibook or 12" PB ? Iam still at school studying interior design so i have to use Autocad extensively. I would like somthing portable to carry with me, but powerful enough to work on my AutoDesk Cad work.
Does anyone try using Autocad desk with virtual pc?
Any sugguestions would be great.

RE: Schhol iBook

I am currently a college student, and just switched to a mac three months ago when I started school. I initailly wanted a 14" iBook because I couldn't imagine a 12" screen. Thank god my dad didn't listen and accidentally got me the 12", because it fits on my desk perfectly. I have never had a problem veiwing the screen, and just love it to death. If I had gotten the 14" I'd be in trouble because it wouldn't fit on my psych desk! I also have virtual PC 6.1 with Xp, and could try running AutoCad 2002 on it if you'd like.

How do u like it so far? How does the VPC perform while running AUTOCAD?
thanks