Which Powermac G4 to run OSX?


Hello, I am wanting to buy a cheap used Powermac G4 to run OSX. I was wondering if a 500mhz, 256mb machine would be fast enough to run it well, or if the dual cpu would be worth the extra money. This would be my first mac and I am basically just wanting to see how it works. I would mostly just be doing basic things, word processing, web surf, but I would also like to ocasionally use Itunes and maybe even Photoshop. Any info would be greatly appreciated!
used macs aren't cheap. look on ebay. you will be looking at about £500 for something that runs OSX effectively (600mhz+ and 512mb RAM)

for that, you may as well buy a brand new mini, 1.2GHz and 512MB ram and an 80gb HDD. Tiger preinstalled.