Hello, new to FORUMS, been trying to build a computer for a long time now. And i NEED some help, this is what i got so far:

-SUS A8N-SLI Premium Socket 939 NVIDIA nForce4 SLI ATX AMD Motherboard

-Western Digital Caviar SE16 WD2500KS 250GB 7200 RPM SATA 3.0Gb/s Hard Drive - OEM

-Saitek PZ30AU Black USB Wired Standard Eclipse Keyboard

-CORSAIR XMS 2GB (2 x 1GB) 184-Pin DDR SDRAM DDR 400 (PC 3200) Unbuffered Dual Channel KIT System Memory Model TWINX2048-3200PRO

-Microsoft Windows XP Home With SP2 - OEM

-AMD Athlon 64 FX60 TOLEDO 1GHz FSB Socket 939 Dual Core Processor Model ADAFX60CDBOX

-Creative SOUND BLASTER X-Fi Fatal1ty FPS 7.1 Channels PCI Interface Sound Card

-XFX PVT70FUND7 Geforce 7800GTX 256MB GDDR3 PCI Express x16 Video Card X2

I got help from a friend on those parts, and what i need help on is finding a computer case, and the cooling devices. Also, I have a question, If i use double Video Card, I will need a power supply of 600W atleast, I havent seen any case coming with more than 500W, So what i have to do is buy a separate power supply and change it, right?