G4 iBook? Those are pretty old. Did you buy a used one? Clearly, it should have been pretty cheap, nowhere near $1000 (
http://lowendmac.com/deals/best-ibook-g4-prices.html). You can get a new Intel MacBook at Apple starting at $999. Of course, if you start picking more features and adding stuff on, prices go up.
Seems like you could work out the problems with the trackpad, since it worked with ubuntu alone. As for iWork, even though I have Macs for all my desktops at both home and work, I use NeoOffice or OpenOffice for that sort of thing. I did buy a copy of MacLink Plus, because I have files dating way back from multiple applications, and NeoOffice can't always open them.
You say, "If it's not an apple, I won't be doing a dual boot." So, why not just run ubuntu on the G4? And then, who cares about iWork anyway? Seems like a non issue, since you are willing to go with a linux only PC laptop. Of course, I can understand wanting something newer than a G4.