I have a 900 or 950 Athlon system I'm not using right now. I had it overclocked over 1gig forever with no problems. Its got a 40gig hard drive, 8 or 12x cd burner, floppy, Windows XP, generic case, 350watt PSU I think.
If you're interested at all in something like that, PM me or email me at pointdablame AT gmail DOT com and I'll get you exact specs and model numbers.