These are my specs so far any help would be greatly apreciated.

Intel Q6600
2 X 2 gb ram Corsair XMS2 DHX TWIN2X DDR2 PC2 6400 800MHZ CL5
8800gts 512mb asus or inno3d. or 9800gts if its less than 340usd in nz.
Asustek P5K-SE Intel P35 ATX motherboard
Seagate Barracuda 320GB 7200.10 SATA2-300 NCQ 16MB 7200rpm OEM hard drive
 TK 965TX-DF V-2.0 650W DUAL FAN 725W MAX
Need advice on a good cheapish case.
 
I got no clue on what type of psu to get. I have read a couple of psu faqs and im still lost.