If you would add your sig we could give you much better advice.
There are charts available on-line that list the watts required for different components. Go here:
Using this chart will help you determine how many watts your computer is using. Add about 20-30% and that will give you a good idea what to buy.
OCZ, Enermax and Antec make good PSU's.
- COOLER MASTER Wave Master TAC-T01-E1C Silver Case
- DFI LanpartyUT nF4 Ultra-D (BIOS = latest)
- AMD Athlon 64 X2 4800+ Toledo 1GHz HT 2 x 1MB L2 Cache
- OCZ 2GB (2 X 1024) DDR (500) PC-4000 EL Gold Gamer Ext. XTC (OCZ5002048ELGEGXT-K)
- OCZ PowerStream OCZ520ADJSLI ATX, BTX, EPS12V 520W
- XFX Geforce 7900 GTX 512MB (665/1630)
- HITACHI Deskstar 7K80 80GB 3.5\" SATA 3.0Gb/s x 2 (RAID)