What should i upgrade next? (gaming rig )

mobo: asus m2n32-sli deluxe

Radeon hd 4850 (512mb) overclocked

4 gb corsair ddr2 800

2 x 150 gb 10,0000 rpm raptor hard drives

amd 64 x2 6400+ (stock at 3.2 ghz)
with stock cooler

machine is used for gaming, and doing a lot of buning

should i buy 4 more gb ram?
a custom cpu cooler?
a big 7200 rpm hard drive for storage?
a new motherboard ?

which should i buy next?

(or list a few things numbered by order of importance)

thanks in advance

I'm not sure I would recommend the AM3 route for you. the change to ddr3 won't give you that much. Plus you're talking new mobo new ram, added cost...

How about a nice quad core? Pretty sure you could drop a PII X4 940 in that mobo and get 3.4-3.5 ghz with the stock cooler. I believe that mobo can handle 140W processors. It will definately outperform that X2. I thnk its about 190US.

4gigs of ram is plenty, although if you go with the Phenom 2 I would recommend 1066Mhz memory to get the most out of it. $50

I do recommend you look at a storagedrive

Those will give you the most boosts w/o a new mobo. in that order.

On the other hand, if you get a crossfire board, two hd4850's in crossfire would be nice, but i didnt see a monitor listed.