I am a recent customer of Mac Mini and love it. Haven't used one since I had a Mac Plus in college.
Because of my work, I track what they do very closely. I have a 17" G4 that I use for demos. VERY nice but I wouldn't call it portable, quite heavy actually. But the screen is STUNNING and the sound is surprisingly good. The latest iBooks are what I'd go for you need something now. But if you can, I'd wait for the Sept 20th show. As reported on several websites, like engadget.com, appleinsider.com, they'll probably have a refresh of the powerbooks before MacTel starts.
If you want good pricing, check out the outlet section on Apple.com. You can get lower prices on refurbs.
