Yea the Mato gears will fit, I had them installed in my by the late Phil who was offering them installed in bare hulls as a package. They're secured with long M3 socket head bolts from the underside of the tank which seems to work very well.
I suppose the new ones would fit too. I'd also try to scrounge up some high-RPM motors as these gears with the Sherman sprocket make for a fairly slow tank.