couldn't you just a Mac mini. this is a 10-minute pickup at a local Apple retail store and you get to save all the time (and subsequently money since time does equal money). for the same $500 you'd get a great computer with CD-RW/DVD drive, a superior video card (ATI 9200), a better processor (G4 with altivec), a clearly superior set of bundled apps (the iLife suite!), and the rock solid Mac OS X that's arguably got all the bennies of Linux with out the spyware dangers of Windows.
i just have no patience for a BYO machine. i've got to get to work!