Here is a set up...3 poles, 18 amps, 24vac coil...$53. If you don't need 18 amps, size down.
Contactor
IC330-18S-10-AC24, Contactor, 18A, 3 Pole, 1NO Aux, Coil: 24VAC, 60Hz | FactoryMation
Protector
IOL-25S-023, Thermal Overload, 3 Pole, 15-23A | FactoryMation