go with a 64 bit I guess.. I personally do not see any point of doing that since no applications/games, etc.. even recognize the 32 bit increase address rate.. according to a few poeple I've spoken to, 64 bit processors will only begin to take advantage of the increase in speeds is another year or so.. so you will be sitting around with all this technology that you cannot even take advantage of..
But, by all means, if you can get a 64 bit cpu that is as fast as a... say.. 2.8ghz cpu (if not faster), then by ALL means go for it, because when the time comes, it will be 2x faster when applications begin to recognize the 64bit techonology in the future..
and by the way, if you didnt know.. everything on a cpu/mobo, etc.. is 64bit (well almost everything) the only thing that isnt is the address speeds, which is 32 bit.. so dont be fooled by poeple trying to sell you 64 bit proccesors with "EVERYTHING" being 64 bit, and trying to skim some money.. i've had people try that on me already..
and also, the 9600 XT is a great card, especially if it can be fully supported on a 8x agp Mobo, but if you are getting top of the line stuff, you might aswell get a x800 pro, if not that, atleast a 9800 pro.. and make sure the manufacturer is radeon themselves, they make a good enough stock-built fan/heatsink on the card, unlike nvidia ( bad experiences )