A 1.5-2Kw AC servo, with a 10:1 gearbox might work.
DMM sells a 1.8Kw servo with 11.5Nm torque. With a 10:1 gearbox, that would give you about 16,000oz-in at 150rpm. And up to 40,000 oz-in of peak torque for a short time.
About $700 for the servo and drive, and probably more for the gearbox.