There are some changes I would recommend here. I assume you won't be overclocking.
The RAM you have selected has 5-5-5-18 timings, I would recommend this kit: http://www.newegg.com/Product/Produc...82E16820144062
It's the same price but runs at 4-4-4-12 timings. And GeIL is a very good brand. 2GB if you choose XP and 4GB for Vista (4X1GB) or two kits. DDR3 is waste of money ATM because it's speed is often limited by the FSB and it therefore all comes down to timings, and DDR3 has much higher latencies than DDR2. If you want the best performance, then get DDR2 1200MHz. Also, 8GB is a waste of money, by the time you will need more than 4, your PC will be outdated and you DDR3 will be the standard and will be available at a reasonable price.
Although the X38 is a nice chipset, I don't think it's worth the extra money over a P35. It does not have a performance advantage, nor does it support any of the new CPUs (the Nehalems will be SKT771) The only advantages it has over the P35 is PCI-E 2.0 support (GPUs don't use all of the bandwidth of PCI-E 1.0a ATM, and I don't think they will for at least another year) and 2x16 lanes Crossfire. But as I don't recommend you do a multi-card setup, this is also not needed. I would recommend this motherboard: http://www.newegg.com/Product/Produc...82E16813128086
The money you save can be better spent elsewhere.
The CPU you selected is from the XEON line, they are server and workstation CPUs. There is a difference between the XEONs and the C2D/C2Q line of CPUs. They both come off the same production line but before they leave the factory. The XEON's L2 Cache is optimized for databases, server activities etc... whilst the C2Ds and C2Qs are optimized for home usage.
Video card: Now here we can put the money we've saved to better use, the 9600GT is nice but it's not an 8800GTS G92: http://www.newegg.com/Product/Produc...82E16814127323
You're also going to need more than the 350W PSU that comes with that case to power this, I recommend this: http://www.newegg.com/Product/Produc...03005&Tpk=610w
I strongly recommend you take my advice because I don't think you should rely on your own knowledge.