What will I need for this?

[Newsboys2004]

Conroe e6400, 2 gigs of ddr2 800 ram, 8 usb devices, 4 hdds, 3 cd rom drives (1 converted to sata using a drive converter), and a x1900gt?

I'm currently using a antec 500 watt power supply...

 

[dBTelos]

Just keep using your Antec, it is plenty.

 

[DrNick]

I agree, you should be fine with your Antec. I would try it at the very least before buying another one but you should be just fine

 

[daphatgrant]

Your antec should be fine. I am assuming it is a SP?