There's an official one: http://www.segaforums.com/hosted/psoarchive/museum/jp.html#eps1_2_pa
And then there is a two track remix mini-disc which was included with a Japanese PSO doujinshi (unofficial, fan-made) manga made by famed anime character designer Ugetsu Hakua. His remixes are actually quite good, as is his artwork. More about Ugetsu Hakua can be read here, he is/was quite the PSO fan back in the day: http://www.segaforums.com/hosted/psoarchive/museum.html#flam
Also one lone, bad beyond belief, main theme remix track is included on a doujinshi music CD titled "Will it Break? Remix". Couldn't possibly recommend it though as every track on that disc is so terrible that they collectively compete with the noise made from someone dragging their finger nails across a chalkboard for entertainment value.
Back on topic though. I like it, you kept it simple in the sense that you took the existing Day Dawns (aka lobby music) track and added the new layer of electronica to it in a complementary way. Good job!
Welcome To The Next Level---SEGA http://www.segaforums.com/hosted/psoarchive/
My collection is what I believe a fan made collection (though I'm not sure how they made it without copyright issues) and has music from: Phantasy Star Phantasy Star 2 Phantasy Star 3 Phantasy Star 4 Phantasy Star Online Phantasy Star Online v.2 Phantasy Star Online Ep. 3.
I think there is the soundtrack to Blue Burst on it also, but I'd have to double check. It's like 6 or 8 CDs worth.
Ripping that collection currently. It's 10 discs total, 9 if you don't count a track listing CD because there isn't any music on it. I tried to search it on google and bing, and I'm guessing I got some guy's work that he did before he got busted so I have a fairly unique item! There is nothing out there on it at all that I found and it's not on ebay anymore. He had them serial numbered and I have 0001 of 2500, though I'd be curious as to how many truly exist. The guy put plenty of work into the collection though, that's for certain. Each disc has different art or graphics on it and they look pretty nice. Maybe I'll take some pics and upload them if anyone is interested.