If you're looking for the Kanon 2006 OP/ED, Nipponsei released it a while back. It should still be seeded via their torrents.
http://nipponsei.minglong.org/ is the URL for their site.
Axersia is correct, AFAIK there is no OST for the 2006 remake, it re-uses game music much like the original did.
For the others, I made a Kanon Music request thread here a while back, but I kind of fulfilled my own request, feel free to dig it up if anything interests you.