I was given the go ahead on upgrading our Macs. A couple of questions concerning OS X and licenses. I maintain eight Macs (4-G4 Desktops, 2-G3 iMacs, 1-G4 PowerBook 667). Which version of OS X to purchase Panther or Tiger? How many OS X do I need to purchase or can I purchase one and install on all? My plan is to install an second internal HD which I can load OS X onto and still be able to boot off existing internal HD for OS 9. Also concerned about RAM, the iMacs only have 384MB (128+256), used as email and internet browsing, PDF files for client approval. The desktop units and PowerBook run Quark, Photoshop, Illustrator and Acrobat, have 2@512MB, 640MB, 896MB and 1.7GB would more RAM help? Open to suggestions.