Greg,
Can't answer your pano head Q.
However I have seen pictures of Polarie setups with a counterweighted dec axis some even holding an ED80 refractor and many holding cameras. Some allow the polar scope to be used at the same time.
http://www.cloudynights.com/topic/48...s-and-polarie/
http://www.astromart.com/classifieds...fied_id=831081
http://www.hkastroforum.net/viewtopic.php?p=270076
Vixen upgraded the payload capacity some months after releasing the product. Nonetheless, be carefull about pushing the weight too far out in the direction of the polar axis.
A well balanced modest load using one of these dec axis/counterweight setups would put less stress than hanging weight out on a long cantilever.
Joe