I second ocremix.org, I am such an addict for that site. I've got around 3 gigs of that stuff sitting on a folder in my desktop for when I need my fix. I got the Ikaruga score as mp3s from some Ikaruga fan site a whiles back, don't remember the site. All that stuff and anime theme songs do nicely for me.
Vampire was a great game (haven't played the new one still), and I remember burning the music to CDs to listen to, but thinking back, I kinda thought most of that music was kinda lame now. Mostly just because it looped so much with little variation, which is OK for a video game.