TS optics make a nice thin (9mm) and light OAG which may or may not work with your setup. It would be an interesting experiment in any case. You can get one from here.
http://apmamerica.com/index.php?main...roducts_id=105
I have several OAG's including the TS OAG 9 which I have used in refractors and SCT scopes. When all the odds fall in your favour they are great, but in most circumstances they are a right pain in the behind. Framing objects to suit your purposes and finding a suitable guide star can be more of a challenge then actually getting the mount and camera to do their stuff. Luv em and hate em at the same time.
Mark