Quiet (ish) motor to drive the tracks

I’m going to make a semi-autonomous robotic tank, I’ll be using the 3" treads. I’d like the robot to be as quiet as economically possible. I don’t really know what to do. I’m looking for something like what micromo.com makes. I’ve looked at the kV rated race-car hobby brushless motors but I’d need to have a slightly more sophisticated control method than that. If anyone can help me out or point me in the right direction, it’d be very appreciated.

I can make my own gears and possible change the bearings if necessary.

You’ll likely want something brushless, using planetary gears. Usually plastic gears are quieter, but companies like Maxon and Faulhauber usually use metal. Why quiet?

If you go very low in kv you might be able to have direct brushless drive.