Nice build. I have something fairly similar, P2 266 (waiting on a 400mhz to arrive in the post), v3 3000, awe64 value & ymf744.
I am using an early asus p2b revision after trying a lucky star 440bx mobo which has sb link (my p2b does not). I had major problems getting the lucky star working with a ymf724 (simply would not recognise sblink in setupds) and a slew of other stability issues.
It's my "kinda fast dos glide pc with a few midi options and sb16/real opl3 support" pc. Built it for Tomb raider, Screamer 2, Descent 1 and more I've yet to discover. I definitely gotta try final fantasy for the XG music even tho im not really into the genre. Are you aware of any other games that use XG? Cheers