Suggestions For Upgrading My System

I'm upgrading my system. My old p3 1gig is not cutting it anymore. I
do a lot of video-editing, converting, etc. I intend to be able to
play the latest games once I upgrade my videocard later on.
I'm in need of suggestions.
I'd like to keep it under $600

P4P800DEULUXE

p4 3gig 800fsb

That's it so far. Heh. I was wondering what type of memory? I'd
like at least a gig.

Does Corsair xms 3200 series play well with the board?
Or should I try Kingston? I understand that I'll need 2 512megs to
enable hyperthreading. Is that correct?

Until I can upgrade my video card, does anyone know if my AIW Radeon
(original) works with the P4P800DEULUXE?

Oh yeah, perhaps a decent case. Preferablly with usb ports in the
front as well.
Thanks for any and all help.