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[Mazeura]

I am currently thinking about building a desktop, and I was wondering if you guys could help me out a bit. I'm either going to keep this for myself, or I am going to sell it (and then use the money to buy myself a small laptop). I plan to be ready to install XP or Vista as well. I'm hoping to make this into a medium gaming rig, possibly into a medium-high, we'll see what happens that is.
This is what I have lined up so far:
Case: Raidmax Smilodon ATX-612WB 69.99$ MIR 20$
PSU: Raidmax Quantum RX-700 700W 109.99$ MIR 30$
Mobo: Asus P5N-E SLI LGA775 119.99$
CPU: Intel Core 2 Duo E7200 2.53GHz 134.99$
Optical Drive: Samsung DVD/CD R/RW 23.99$
Hard Drive: WD Caviar 640GB 7200RPM 16MB cache (SATAII) 114.99$
(The Case and PSU are a combo deal, total price 154.98$ then the two MIR's.)
Those are the things that I know that I am going to get for certain. I would of gone with the Antec 900 and a different PSU, but the case I got has a combo deal with the PSU that would only cost 100$ to get after MIR's, while the Antec combo would still be 150$. I've read both reviews on the PSU's and they seem to both be good, so I rationalized not getting the Antec 900 and the 650W and go with what I chose.

Now for the things that I am debating. I am going to put at least 2GB of RAM into this, and I am debating whether or not to put 4GB in. I also do not know what voltages my mobo supports for the RAM, so help there would also be beneficial.
RAM DDR2 800:
CORSAIR Dominator 2GB (2X1GB) 149.99$ MIR 40$ Timings 3-4-3-9 Note: If I got this, I would only get one of it. (2.4V)
G.Skill 2GB (2X1GB) 44.99$ Timings 5-5-5-15 (1.8-2.0V)
OCZ Reaper HPC Edition 2GB (2X1GB) 69.99$ MIR 30$ Timings 4-4-4-15 2T (2.1V)
mushkin 2GB (2X1GB) 47.99$ MIR 10$ Timing 4-5-4-11 (2.1-2.2V)

I honestly want to go with the mushkin RAM, but as I said, I don't know for sure what the voltages supported are for that mobo.

The graphics card is one thing that I am having the most problem deciding about. I used to know a lot about nVidia's GPU's, but I haven't kept up with the 9series, and the newer 8series. So I'm kinda of lost here.
I'm trying to keep the price to 140$ max (after MIR's and other savings) as well, which limits my options quite a bit. I am also considering SLI'ing two cheaper GPU's (most likely 2 8600GT's) instead of getting a single card.
The current card that I am leaning towards is:
Gigabyte 8800GT 256MB 147.99$ MIR 30$ (OC'd to 700MHz) GDDR3
But I am also considering, as a 2nd choice:
Asus EN9600GT silent 159.99$ MIR 20$ Note: As it says, it has a passive cooler on it, which I like because it usually bugs me when I hear the GPU's fan going. It is at stock settings as well.
The other cards that I'm looking at are (and this is a long list, so I am just going to post the url and the name, and if there is an OC or passive cooler):
MSI NX8800GTS 320MB (GDDR3)
Palit NE/9600GT 512MB
EVGA 8800GS 384MB (GDDR3) OC'd to 650MHz
XFX 8600GT 256MB (GDDR3) Plan to SLI this, since it would cost 70$ after MIR. Double Lifetime Warranty
Leadtek 8600GT 512MB (GDDR2) Plan to SLI this as well since after MIR it would cost less than 70$. Though I have never heard of this company, reviews have been decent on this card.
Chaintech 8600GT 256MB (GDDR3) Plan to SLI this as well, since price under 70$ after MIR. Haven't heard of chaintech either, but reviews have been decent on card.
XFX 9600GT 512MB OC'd to 680MHz


Any help would be awesome, and if you have a suggestion on what to get instead of what I selected currently, please feel free to suggest it. Yes, I know I could get a quad core for about 60$ more, but I don't think that it is needed because the CPU that I chose I should be able to OC quite a bit without any problems.
I also might go for a smaller HD as well, I just haven't decided yet for sure, but it's safe for me to over-estimate prices so that I can save up the money for everything and make sure I have everything.