I notice you mention the Futaba T6XA. The one I have is an excellent radio and with other flight paks I use it often. I have several other radios that work well but like the T6XA best.
RE: your P (F) 51. Just remember that all fighters are inherently unstable. They're designed that way for manuevarability. Unfortunately for us the scale models of the aircraft inherit the same qualities. Some have a bit more stability designed in but a true scale will have the same flight characteristics. 51s with scale gear have a great tencency to do three point landings. Spinner and main gear.