I think the quickest and easiest way to get their releases is using BT. The link is given in the topic message. read it for yourself.
Another way, and the typical way used on irc, is to get them from the bots and fserves running on the channel. type !list to get all the info.
To find more anime osts, you might want to go to #anime-ost and #animemp3. These two channels have been running in service for quite some time~
Bests,
