good luck getting ram that cheap.
Is the audigy in Canadabucks? I can get a platinum for under 160 US. And a normal audigy 6.1 for under a hundred. Buy better ram.
Why the hell are you thinking about going phase change if you are not willing to spend a few extra bucks on good ram that will clock at or higher than it's rated speed? If you put the system together, find out that your ram can't hold it's own even at the most relaxed timings you have wasted a good phase change system.
Get a phase change system only if you are going to go balls out and buy the highest quality equipment possible.
Otherwise, save yourself a couple hundred and get a decent water cooling setup. You will probably hit the limits of your sytem before you hit the max cooling power of the h2o setup. Besides you are using a P4, which runs cooler.
Save yourself some money to get a good system and go hang out with the waterboys.
Unless of course you are willing to spend some more money, get the best components you can buy, and be prepared to lose it all if you fubar the phase change or get condensation.
Are you really prepared for that risk?