AndyG, I jusy did the same thing you are doing right now. truth be told this weekend i am going to be unlocking the mult. on my amd and over clocking it since i was just now able to get the good hsf, and case fan to draw off the heat.
The problem I ran into was, the hdd would not boot up at all since it was a new mobo chip and ram, it would go to post and sit there for about five minutes until it gave up. I ended up reinstalling windows to get past that. Other than that I think you should be good to go, good luck man.
dfi nfII ultr infinity/asus p4s800
amd 2500xp m/p4 2.6
ati 9600/ati 9600 pro
512mb pc3200/512mb pc3200