I strongly urge you to keep the Mustang hanging from your ceiling for the time being. My first plane was a 48" Mustang. I was lucky enough not to find anyone who would test fly it for me, and smart enough not to try myself. I sold it for a proper High-Wing Trainer. I learned to fly easy enough, and soon had another beautiful Mustang as my third plane. Except, even after a year of flying a trainer, I got the Mustang into a spin I couldn't get out of on my first flight. To an experienced modeler, flying a Mustang is not all that hard, but it is easy to forget just how quick a flight can turn bad with this type of plane.

If you really want a mustang as your first plane, by the Hanger 9 Mustang PTS, and transplant your radio gear. With your 65LA, it should pull a 13-5 prop if you have the ground clearance. The "5" pitch will help you keep your speed down, and will tend to airbrake your plane on landing.

I currently fly an EZ P-51 with a Saito .82 and a 11-10 prop. Lots of fun, and pushes near 100mph on the fly-by's. Your turn will come!