With a 68" wing span you will ruin a nice wing loading with that g23. It weighs about as much as a zdz 40 and has no more power than a 4 stroke 150. I would look for a used ys 120 or go to a saito 150. even a 2 stroke 120 should be enough motor to hover a 10 - 10+ pound plane. If I were you I would put the ys 91 you allready have in it and see how it does.
nice plane by the way