single and 3 phase motor sizing and mounting ?

[m_c]

Capacitor start motors (I think officialy they should be called capacitor start/capacitor run) use a centrifugal switch to disconnect the start capacitor once upto speed, otherwise the motor will cook itself pretty quickly.

Having said that, a 3phase and VFD is probably a more practical option. If a high startup load is involved, you might need to oversize the VFD a bit to give a bit more current for startup purposes.

[EddyCurrent]

According to the data sheets the 0.75kw 3 phase 4 pole motor produces about 5.1Nm torque but you have to go to a 1.5kw single phase 4 pole motor for that same torque.