I'm gunna sell my laptop since it is useless now so I need help building a new pc. Or, if there is a great gaming pc for under or around my budget I might manage. I've been away from pc gaming in general for a year now so I don't know whats in and whats out.

Budget: $900 or less

All I really need to run is UT3 on medium/low graphics and Q4 on medium/high.