I just rebuilt my system with an Intel 865PERL MB and the same Corsair XMS DDR400 memory mentioned above (3200LL). The Corsair has a very aggressive SPD programming- it tells the MB to set the memory timing to a value that (in my system) causes the Corsair memory to fail repeatedly and often. I had to manually back the timing off to 2-3-2-6 -1T (from the SPD setting of 2-2-2-6 -1T). Just a note to check this if you use the Corsair memory and run into trouble.
A note about your power supply- it has enough watts but P4 motherboards often demand to have the special P4 2x2 12V extra power connector (12V-ATX). If your current PS doesn't have this then I think you either need to replace it or add some adapter. My MB says it won't even boot without that power connected.
