Some of the GP kits mentioned in this thread may be discontinued but Tower let me add 9 of each to the shopping cart on June 6, 2009 and it showed they are in stock ready to ship.
40 size Extra http://www3.towerhobbies.com/cgi-bin...?&I=LXJ579&P=0
60 size Extra http://www3.towerhobbies.com/cgi-bin...?&I=LXJ580&P=0
40 size Cap http://www3.towerhobbies.com/cgi-bin...&I=LXJ578&P=SM