updating OSX - URGENT!

Hi all

A friend of mine is wanting to format his powerbook (with the intention of then running FCS2), but the installation discs he has are for Panther 10.3 and he wants Tiger. If he reinstalls this OS will he be able to simply upgrade to 10.4 with online updates? This isn't really my thing and I'm not sure what the deal is with upgrades and the like so thought I'd put it to you guys.

The only thing is he's starting an edit job tomorrow and doesn't want to take the time to reinstall an OS that won't run FCS2, so he's having a mild freak out.

Any advice would be great.
Mat.