Hi Paul, The WO PFlat 2 reducer flattener is designed for a DSLR size chip but again requires spacing of about 55mm from the chip.
This works very well with my Sywatcher ED80 (same as the Orion).
Available from
www.andrewscom.com.au
P-FLAT2 NEW 2" APO field flattener, 0.8x reducer, for refractors. Includes 2" adaptor. $249.00