Budget builder! need advice plz!

Okay! we'll I've been doing some research the past few days and I've come to a pretty decent budget build I guess. I use the computer for mostly school, but want soome gaming capabilties for past and present games. (not looking to extremely future proof or multitask) I'm currently running a stock dell e510, with pent4 3.0ghz and 128mb 32bit graphics, so I figure I can't go wrong with any budget upgrade at this moment. anywho, heres what I got so far, feel free to make suggestions. I'm not too concerned with my budget, but I am cheap, also, I don't plan to upgrade further anytime soon.

CPU - e2160 (OC to 3.0)
MOBO - GIGABYTE GA-P35-DS3L
PSU - CORSAIR CMPSU-450VX
RAM - 2GB CORSAIR XMS2 DDR2 800 PC2 6400C4
GPU - Sapphire Radeon X1950PRO 256mb 256bit
Case - Coolermaster Centurion 5

I had originally planned on getting a Geforce 8800GT, but due to limited availability and price, and the fact I dont play games 24/7 I don't think I really need it for my budget, yet, if you guys think it would be a good a buy, let me know.
In addition, if I did decide to purchase the 8800gt, should I consider buying an Intel Core Duo e6750 alongside?
Those two upgrades would only put me at about $250 above my current build, but considering my PC usage, would they be worthwhile?

One last thought! I was browsing for a good PC case, and I settled on the Coolermaster Centurion 5, but I think I like the look of the upcoming Raidmax Sagitta 2 case (releases 12/14/07). It's listed on newegg at only $40 more, and looks to have better cooling, should I consider purchasing this?

http://www.newegg.com/Product/Prod [...] 6811156090

Stay with the 8800GT. Best Price vs. Performance atm, but if you really must have something now - there is always the ATI 3850 / 3870. The 8800GT still beats them in performance though.

If you're not gonna run Vista for a while, the X1950PRO is fine. If there's a Circuit City near you, check it out as they have the card on sale for about $100 after rebate.

http://www.circuitcity.com/ssm/Vis [...] dp0t653050

CM690 is getting rave reviews:

http://www.newegg.com/Product/Prod [...] 6811119137

The E6750 is the best bang for non-overclockers. It looks like you're an overclocker. Keep the cpu. Get a good cpu cooler.

The Abit IP35-E is cheaper than the DS3L. Both are P35 & good overclockers.

http://www.newegg.com/Product/Prod [...] 6811156090

That the case? Looks very Transformer-ish. 3 120mm fan mounts. Good cooling. Go for it if you want. After all, it's your pc.