Need Help With Choice On Mac Options

[Amathus]

Hi there, just this second registered and hello to you all.

I did a bit of searching before i registered hoping to find answeres to my questions but everything seems a bit wishy washy and cant seem to find clear info.

Basically im looking to purchase a Mac with Logic Pro 7 over the next few weeks and i know very little about them both.

Ideally im looking to get a powerbook to easily take it around with me but still i'm unsure that the powerbook or any of the laptops have enough power to run logic with no issues.
I would be grateful if somebody can point out and tell me exactly what mac is best for running logic and if a powerbook has adequate power to run it.
Will it be pushing it? or should it be difficult to crash it

And in terms of general music production on a powerbook, is it easier or harder on a laptop then a desktop? i.e are laptop soundcards just as good as desktop.

Money is not a massive issue but i was looking at not going over the £1500 on the mac itself

Forgive me if im sounding unclear but i would be extremley thankful if someone can help me!

thanks in advance