quasian is indeed the artist, he has made a lot of other songs as well. As for the tracker.. I myself always use MadTracker 2. To me, it's the tracker that's easiest to handle, but that's just my opinion. Just try a couple of 'em out.
As for the samples of stream of lethe, you will find them, where else, in the song itself. Just pop up the song and you will see the samples as well.