BTW, I load tested my inexpensive BBQ rotisserie motor over the weekend, probably not enough torque for even '5 gal'-14 lbs grain.
Go to the scrap yard and get an old windshield wiper motor. I've seen a few people use them. I figure if it's too fast, just attatch a chain and sprocket to reduce the RPM at the paddles. The chain would make hooking up a double paddle system pretty easy for my system.