I am building a SSE from a kit, but I really wanted to fly it so I got the ARF version, too. Also, the LHS had a really great deal on it - $150.00. I could not pass it up. My power plant is going to be a OS FS-70 Surpass II. I wanted to know what prop size I should use. 12 x 6? 13 x 4? I know I have to change out the landing gear. I am putting in a Dubro landing gear.

Thanks in advance

EDIT: What size prop should I used to break-in the engine?