Well, in the mean time try these:

http://www.peachparts.com/shopforum/search.php?action=showresults&searchid=900674&sortby=lastpost&sortorder=descending

http://www.peachparts.com/shopforum/showthread.php?threadid=44597&highlight=orthopedic+seats

http://www.peachparts.com/shopforum/showthread.php?threadid=18881&highlight=orthopedic+seats