What do you think of these?
https://www.crowdsupply.com/iq-motion-control/iq-motor-modul...
Am thinking they'd not have enough torque, unless you gear them pretty high.
They are basically a stepper motor from the application's point of view, but with some of the advantages of a servo, as far as I can tell.
(No affiliation, just curious if these guys are onto something useful.)