Well I have about $400 dollars to spend on a computer. The thing is that I cant decide weather to upgrade my Mac or buy a new one. My Mac is pretty basic, 15" iMac, 256 MB RAM, 80 GB HD. But I also build computers and for $400 I could build an AMD system with 256 MB RAM, AMD 2500+, 40 GB HD, DVD-ROM, with Windows home and Red Hat installed. But I have a few questions: My Mac seems really slow, so I was gonna upgrade it to 768 MB of RAM, and buy an external 160 GB HD for backups.I want to get the AMD system but the thing is that my iMac's HD keeps making this clicking noies, and I'm afrade that the drive migh fail. So I basically have 3 options: 1) Buy a 512 stick of RAM, and a 160 GB HD to put in my iMac. or 2) Get the AMD system (and eventually save up enough money to buy an internal HD, put it in the AMD, and net work the computers together and transfer the files that way) What do you think is best?