If you get any of the Macs with G4 or G5 chips in them, you won't be compatible with much of the newer software and OS versions. If it were me, I would look at something much newer with Intel CPUs in them. You'll spend more money for sure, but I think you'll be much happier.
The PowerPCs that came before the Intel changeover were plenty powerful enough in their day, but that day is long past.
Thats what I was afraid of. Incompatability, I wondered why the G4 17" laps were so cheap. Glad I asked, no shame in askin questions. Assume will make an ass out of u and me...