anybody give me a good idea for my new powerbook?

I have the same with 3/4g RAM.

I run Logic 6 Gold and Reason and get latency issues when rewiring Reason into Logic.

If you want to do any audio recording I would go for a Logic only set-up and buy yourself a decent third party drum machine plugin. Its a complicated beast at first but once you get comfortable with it its lovely. The Logic Pro set-up soon to be released has everything you could ever want for minus a drum machine.