I want a Mac, and I would love an iMac, but I am not sure I can wait that long to save up $2000. I really want to start using OS X. I am so tired of using Windows and want to get on a Unix based platform. What I do not know is what are the basic requirements to run OS X at a reasonable speed. I would like some opinions on what would be the base specs to run OS X and not be frustrated? As in MHz, RAM, Etc .. I do not plan on doing anything hard core, just using all the iSoftware is about it. Also are there any old Power Macs I should stay away from because of OS X compatibility reasons, and if I wanted could I add a superdrive and not run into compatibility problems?. Bottom line is what is the least amount of money I can spend on a decent OS X compatible Mac.