I fly with both the 2200 3s, and a 1050 3s in my FT Mustang. The bigger one (2200) has to be set farther back to get the right C of G. So for ease of battery install, I go with the 1050. For long duration flight, I go 2200. Just mark your battery compartment once you decide what you want to go with.
FT Mustang is pretty much my favorite FT model. Better than the Spitfire, Sportster, and Scout. As far as scratchbuilt DTFB planes go, I haven't found one as forgiving and enjoyable. I run mine on a C pack, and run low rate servos on my transmitter.
I went flying yesterday for the first time in several months. What were my go-to planes? A mini P-47 Thunderbolt based on the mini Scout, and of course, the FT Mustang. The mini got my flying legs back under me, and the Mustang was for pure joy.
Good luck, will tune in for video/results.