I just maidened my S.E. yesterday as well. YS .63 spinning a 12X7 APC. Stock landing gear, stock size wheels. There is plenty of clearance for a 12" prop. If you fly from pavement and don't dork your landings, there's room for a 13" as well.

BTW, my S.E. took two clicks of left aileron, four clicks right rudder and that was it! Good flying model. I can't wait for calmer winds so I can really trim it out.

John