Upgrade from 10.3?

[macincrotch]

I've reformatted the hd, installed 10.3 and I'm back up and running. I need to reinstall Adobe CS3, but need at least 10.4 to run it. Before my hd crashed I was running 10.5 and moving along decently. My question: Should I buy and install 10.4 or 10.5? What will give me better performance based on my older G4 trying to run this software? Also, any recommendations on where I can find the older discs without costing too much?

 

[Giaguara]

In the long run, 10.5 is probably better. Including future upgrades and compatibility of other programs, and if you'll later sell the Mac when upgrading to a different model, you'll get a better deal for it.
You didn't specify which G4 you have - so as long as it will meet the requirements for 10.5, and you'll maximize the RAM (10.5 with anything less than 1 GB is slow, and to use it fast and smooth I'd say get at least 2 GB RAM in total) I'd say go for that. You should be able to find both discs at ebay, amazon etc. When purchasing the discs, verify that the discs are black in color - the retail discs have always that color (and the Mac specific discs that are gray won't work on other models or versions of Macs than they were bundled for).
But if the specs are better suited for 10.4, that's not a bad choice either. Again, RAM will make the beast run happier.