Well, if you look at that other thread, it looks like they are basically saying the same thing. Get an A-64 processor, it will be much better than the XP.
Like I said before, if you don't care about upgrading, socket 754 will be fine, as will AGP.
If there is any way you can swing the 6600GT along with it you will have a great build for that price range.
BE HEARD - Techonvent
DS3 | E6400 - 3.2GHz 24/7 | 2GB OCZ PLat. PC6400 | 6800GT | Zippy 460W
What the world needs is more geniuses with humility, there are so few of us left.