The HeiMotion Premium brushless AC servo motor family from Allied Motion Technologies is available in five metric frame sizes with rated torque from 0.12 to 14.4 Nm, and continuous shaft power from 50 ...

Have you had a look at something like the HS-785HB Winch Servo Motor – Rotation = 1260 degrees (3.5 turns) Much less messing around, but not sure it will have the resolution you need.