Xmas budget computer help.

[Ivan275]

Hi, I would like to get a computer in about a month and would like some input from people that know this stuff better then me. I currently have an ageing:

ESC K7VTA3 MotherBoard
AMD Athlon XP 2400+
512MB DDR PC2700
Nvidia GeForce FX 5200 128MB
WD 80GB ATA100 8MB Cache 7200RPM HD
?? 12GB ?? HD (sys backup)

I am thinking of spending about $500 but I think it will be more like $700 for a mid lvl gaming PC. I'm currently thinking of something like this(my) wish-list
//EDIT: LIST REMOVED

I was wondering if you can give me some suggestions that are in a similar price range?
Is there something on my list that totally sux and need changing?
Is there anything that wont get the best performance because of the other components?
Is there anything that I can downgrade so the price is less and still have about the same performance?
Are 2x512 DDR better then 1gb DDR?

PS. I may do a little overclocking on this but not much.
I will be keeping my DVD RW, keyboard, monuse and monitor.

[Ivan275]

Thank you everyone for all your help, I just put my PC together and I couldn't have done it without you all.

[JPMiller]

Poor choice of Power Supplies...
Stay away from Ultra...
Stick with the better brands, Fortron, Antec, OCZ, Etc....
Unless your planning to overclock, there is no reason to spend extra on high-end Ram... go with midrange memory having the correct speed for your processor...
Anything more will be a waste of money...also... Just so your aware, your motherboard does not list your brand or type of memory in its compatibility list...
Wich on one hand means little, but on the otherhand may make a difference when assembling...

[Orun-sal]

That Video card is making me cry. I have that also and it can't play games for crap.