Ok,
While everyone else argues about a "standard" voltage for microwave oven turntable motors, Ill just keep myself busy actually answering the OPs ORIGINAL QUESTION
The one in the Addison Electronics listing, in the middle is 120vac, at the rpm you desire...sems to be a good choice, although its 5rpm, and you have specified 3 or 4... I dont think that 1 more rpm is gonna kill you as far as cake rotation goes.
you know me....helpful to the bitter end....
Christ, I hope this doesnt add any positive points to my standing...
AAAAHHH, Addison Electronics, absoutely wonderful parts shop in Montreal. One of the few where you can still get tv parts, and anything else electronic. one of the fe true "Surplus" electronics stores around. Their catalogue is autrocious, but man, you go there and i doubt that anyone here would leave without at least 100.00 in parts, and surplus. Ive ordered from that place since I was 9....(as he wipes a tear from the wrinkled corners of his eyes)