I picked up two more Power Mac's yesterday on Craigslist. I got a 300MHz G3 and a 450MHz G4. It got me thinking about upgrading them to the best of their ability. So I was just wondering if someone could point me in the direct of where to purchase these upgrades or is just keeping an eye out for them when they pop up the best options? I also have a 450MHz G4 Cube that I would like to upgrade as well.