Decide on the size warbird you want..I do suggest 90-1.20 size or bigger

Buy the motor and servos that will be suitable to fly that warbird selection

Then buy a simpler low wing sport aircraft and use the engine and radio to fly it.

Once satisfied with the sport aircraft and engine performance/tuning procedures, swap everything into your chosen warbird

For example, purchase a H9 Funtana 125 with OS 120 or Saito or YS 110 and good servos
Enjoy the heck out of it, then transfer all gear into an Top Flite P47 1.20 size

Aquire aircraft that have been around for a bit, and have user and parts support.

If considering gasoline engines, please check into total weight, exhaust size and fitment to airplanes, prop clearance etc

In my opinion, I would likely use a glow engine 2 stroke or 4 stroke in a sub 70 inch plane.

I would also check around for a used low wing sport plane