Weldiger, sorry to tell you, but the G4 iMac doesn't quite make it in the system requirements dept. for Leopard.
http://www.apple.com/macosx/techspecs/(There is a work around - see:
http://www.macosxhints.com/article.php?sto...071026083746346 if you really want to try it - but you'll need to get the beast to read the DVD first!!)
The 700MHz G4 iMac shipped with a CD/RW combo drive - it should be able to read the install DVDs for 10.4 and 10.5. Not sure what is going on there. Do you have a backup of 10.4 anywhere that you could use to clone to the 700 GHz iMac if all else fails?