Yeah, I guessed you weren't going to SLI, what with the IP35 Pro that doesn't support SLI. Yes, it is a friendly and very good mobo. It's a bit slower than others when it comes to networking, but very good from all other points of view. I think it was the most popular at newegg at some point.
Good case. VERY good PSU (heck, I have one like that) but overkill for one video card. Maybe get the 610W version. True, I have the 750W version for a single card myself, but my card is a GTX and consumes more, and I do intend to change the motherboard and do SLI later. On the other hand, if you have the money, the 750W is more future-proof so why not.
E6750 is great bang for the buck. If you want more future-proofing get a Q6600 instead.
Crucial Ballistix is very good, and the Arctic Cooling Freezer is perfect for stock or mild overclock. You did your homework pretty well. I'd only replace the Raptor with a WD7500AAKS - about the same money, about the same speed, 5 times the size.
Any plans for speakers, sound card, DVD burner, monitor?
A fabulous burner would be PX-810SA. A good burner that costs much less is Samsung SH-S203B
X-Fi sound cards are fine on XP. If you intend to move to Vista get an HT Omega card instead. The integrated audio may be just fine for your needs anyway.
With that card I'd say a 24" or larger monitor will disappoint in some games, so stick with 20" or 21.6" or 22", i.e. 1680x1050. I like Samsung and LG and Viewsonic, for example.
There's an aftermarket cooler called Accelero S1 for the 8800GT, getting great reviews. I'm not saying buy it, but do some research. Some people are saying it reduced the noise and the temperature of the card a lot.
Looks all good except the Raptor HD. I'd get 2 x 320g HD's put in RAID 0 configuration and have more than 2x HD space. All of the other parts are nice, so you can change them to get a q6600 if you like, but that is up to you. Here is what I'd spend on certain parts if you want fit a q6600 into the build.
q6600 - $280
mobo - ~$130 Abit IP35
PSU - ~$100 Corsair hx520w More than enough for any single GPU setup.
Memory - $50 for quality CAS4 DDR2 800mHz RAM, just like the ones you selected!
HD(s) - $160 for 2x320gig HD's in RAID 0 configuration or just use a 500 or 750 gig single HD to compliment a smaller HD for the OS.
CPU cooler is a budget OC'ing HSF that you selected (AC Pro7). If you want more extreme OC'ing than the TT 120 is pretty popular.
Case - ~$100 or less CM 690 case or Antec 900 at the upper end.
These are just what I'd do, what you have is fine, just showing you that you can fit the q6600 into your budget, "if" you want to.
Compared to older disks, yes. Trees that appear in Oblivion at the wrong time with the older disks, now appear when they should, etc. But, compared to the newer disks with PMR, the Raptor is really not that hot. It's still faster, in some benchmarks, but not by much.
I like that RAID 0 idea. The only problem with it is when a disk dies you lose the data on the other too. Just back up often. With RAID 0 you won't beat the Raptor when accessing lots of small files, but you will beat it when accessing a few large files. Same thing with WD7500AAKS or Spinpoint F1, in fact.
Thanks for all the advice. This computer will be strictly for gaming. So I think a single 150gig Hardrive will be plenty. I chose the 6750 because of a good savings in $$$. Plus Im going to overclock for my 1st time, so less to spend if I mess up lol.