If you decide to go with the Q9300, then pick the Q6600 instead, as although the Q9300 is 45nm, it only has 6MB of L2 cache compared to the Q6600's 8MB. The P5E is a great mobo and a few people at CF have one and seem happy with it.
Option 1: It depends what resolution you play games at and whether you play with filters or not. If you play no more 1280x1024 with AA or 1680x1050 with no AA, then the 8800GS is the better choice as it has 96 stream processors compared to the 9600GT's 64. The disadvantage is that it has 384MB of VRAM, but it will outperform the 9600GT if you don't play at very high resolutions: http://www.newegg.com/Product/Produc...82E16814130333
Option 2: The 9800GTX is a bit of a dirty marketing trick on Nvidia's part. Although it is part of the 9 series, it is no different from an 8800GTS 512MB apart from slightly higher clock speeds. And you can OC the GTS to those speeds anyway using Rivatuner, save your money and get the GTS instead: http://www.newegg.com/Product/Produc...82E16814127325
Option 3: My advice is not to pay extra for factory overclocked cards unless they are non-reference designs with improved coolers etc.
HDD: Raptors are nice but I don't think they are worth it. They are very expensive and it's not worth the extra cost just to cut a couple of seconds ff your loading times. For cheaper, you can get a 500GB 7200RPM drive with a 32MB cache which will be more than fast enough: http://www.newegg.com/Product/Produc...82E16822148288
Memory: You should be looking for DDR2 800MHz with CAS 4 timings. 4GB is nice if y are running Vista. I like Corsair XMS2 and would recommend it to anyone, it does tend to be a bit more expensive though. Mushkin also make some great RAM, and that OCZ kit is very good for the price.
PSU: This is a brilliant PSU for the price: http://www.newegg.com/Product/Produc...82E16817341010
It features quad 12V rails and is manufactured by the FSP Group who make reliable and solid power supplys.
Hope all that helped.