If I had your system and $1000 I would buy a really good PSU for around $150 (Antec, OCZ, Enermax, Forton etc), a 6800 GT for around $400, 1gig Crucial Ballistix memory for around $300 and then a new CPU such as a retail AMD 64 3000 for $160 or so. Then you could sell your old parts and use the...