Hi loopy and silvinator,
Maybe we need to contact Dave from Aust Sky and Space. He mentioned in another post that he teaches astronomy at college. http://www.iceinspace.com/forum/showthread.php?s=&threadid=245
I ask him about it in the post but didn't get a reply. Maybe a more direct approach (like ringing him at AS&S) might be the go. Or maybe he may know which of the two you've ben looking at is the way to go.
If you read this Dave "Sorry for putting you in"
Clear skies
Paul