Replying to Help: Macbook Pro for Graphic Design

Hey all of you Mac user out there! So I am headed to an art college this coming fall for graphic design. Anyways, I have to purchase a Macbook Pro along with the Adobe CS4 or 5 Suite. My question is what Macbook Pro should I get?

Processor speed?

Screen size, 13" or 15"? I already have a 20" LCD monitor right in front of me for home use.

RAM/Memory?

I would assume a 500GB harddrive?

Let me know if I need to tell you more. Thanks!