Would Windows XP Professional or Vista 64-bit better suit the gaming PC I am building? (Specs Includ

The specs are located at this web address.

www.dolanauctions.com/computer.html

Any other suggestions would be great too

Would Windows XP Professional or Vista 64-bit better suit the gaming PC I am building? (Specs Included)?windows media

You have 4GB of RAM there, hence you need a 64-bit OS to run it. So, go with Vista 64, pretty easy.

Now I just have to ask, is there any particular reason you are spending so much money on that motherboard, and then putting only one CPU on it. The only benefit that board has its ability to run 2 CPUs, hence you are wasting money buying it and then only putting one CPU, especially when that one CPU is also the same speed as a 6000+, which could be had for half the money.

Would Windows XP Professional or Vista 64-bit better suit the gaming PC I am building? (Specs Included)?microsoft exchange internet explorer

Vista hands down. I do not normally advise installing Vista, but Vista supports all the latest games and handles them better than XP. Your system is fast enough that running Vista will not slow it down to a noticeable amount.
I would say Vista. With Direct X 10 and the crazy super specs you have, Vista will run so fast, and the games! If you want XP Pro, The 4GB and that woun't be as needed unlike Vista but there are more games (currently) that just supports up to XP. So if you can't wait and want to game now with the older games that aren't compatible with Vista yet go XP, otherwise Vista and wait until it is compatible. So... I say Vista for me :D

Oh did I forget to mention that games such as Halo 2 is only Vista... So new games goes Vista!