Futaba 9001 is pretty good choice. It is quite precise, good centering, relatively in-expensive ($29.99) and has a torque of 72oz-in @ 6v. The motor is coreless which is a big plus. I use two for ailerons on my Venus II (a 90 size pattern ship). The 9001s should be good enough on all control surfaces for your 45-60 size application.