Wow, I wish people around here through out broken apple hardware. Any of those would sell for $500+ on ebay.

The main thing to know is that the intel macs won't install from just any OSX CD, it has to be the restore CD that came with that model. I'm not sure how specific they are, but a mac mini DVD set won't work in a macbook. If you could some how come into a Leopard DVD, you might have more luck, as that's going to have to support everything.

Target disk mode should work just fine, the boot options on modern macs are amazing. You should be able to boot it off the DVD of the powerbook using target disk mode, and you can install to an external drive and use that as your main boot disk. (Heck, you could install OSX back onto the powerbook's HD at the same time... the powerbook would stop booting, unfortunately)

Matthew