im interested as well. i heard them a while back but i think i remember the vocals bothering me. i was expecting to hear jarboe, maybe i listened to the wrong album.
there's a new 2008 album called "Dragging A Dead Deer Up A Hill" which is the release that got me into grouper.
http://www.typerecords.com/releases/full.php?id=49
this page shows more releases..
http://www.boomkat.com/artist.cfm?a=10370