Yes, albums used to be available but, like most vinyl, are long gone.
 
Yes, videos used to be available and maybe still are, though I've been told
that they're not.  I have three of the four video collections (Grammar,
History, Science: missing Multiplication) and would recommend them almost
whole-heartedly.  The only problem with them is that they are introduced/
moderated by Cloris Leachman (clearly hard up for funds) and a bunch of
"cute kids" who are singing really horrible songs and look like they're all
been gassed with happiness drug.  It's too bad to even be enjoyable, but I
look at it as penance for getting to the good stuff.
 
I heard that ABC was going to put them back on the air this season, but
don't know whatever came of that.
 
In terms of the cover band thing, I had heard about the compilation album
as well, but that was a while back and those things fall apart easily, so
who knows.  A former band of mine did a SR medley, so I know many lyrics &
music, if that's what you're looking for.
 
Personal favorite:
 
Rufus Xavier Sasparilla (a tremendous ad for pronouns)
 
Good luck finding what you're looking for & let me know if I can help.