The 2/3 scale P-51 looks like the great, the prop that they use is a Cutdown Kingair prop. The gear reduction system is the weak point on the engine. The shaft going to the prop snaps easily. I had to tow one back to the hanger 2 times, it belonged to a freind of mine. The other problem with it was the gear, it had 4 switches to raise and lower it, one to turn the power on to the system, one to raise and lower the gear, one to raise and lower the gear doors, and one to raise and lower the tailwheel, it was a nightmare. They may have got it fixed but at the time I was around it there was no fix.
They are also making a composite full scale P-51 powered by an Allison turbine, that would be a blast. In reference to what makes an airplane fly, It isnt thrust, it isnt lift. If you dont have money you aint flying.