Always keep one thing in mind when running/installing OS X. os x LOVES ram. You can never have enough of it. if you can get 2 256 meg chips in there, It will probably triple your overall prformance. I'm sure you know what your doing with these machines, but they are a pain in the @$$ to work on, so this guide: may help. If you have it, once and if you do the ram upgrade, 10.3 will run great on that ol' workhorse.
Mobile-2.2Ghtz Core 2 Macbook, 4GB ram, 160GB HDD
Server-Dual 1.42 MDD G4, 1GB ram, 4 random hard drives.
PC-C2D 2.4Ghtz, Asus Commando, 2Gb ram, 3 hdd's in raid 5, 8800GTS.