I see Orion is selling these guide scopes.
http://www.telescope.com/control/pro...oduct_id=07380
They appear to be the same as the ones AstroPhysics import and sell for much more.
I would though buy the AP ring set for this rather than the Orion ones. They "look" a bit flimsy and you don't want flexure from weak rings/plates.
Greg.