Let's see, your "pot" can weigh a ton. So, you're mashing about 500 pounds of grain, with say, 1.5 qt. H2O/lb.? Since you're dealing with that much grain and no doubt, a seasoned professional, using a fine "pot". Buy an auger drive designed for moving mash. Used, they start at about 3 grand. Of course, you'll need to weld all kind of gizmonics to the "pot" to make it work. Now, if you wanna be a Wanna Be Rube Goldberg. You can remove the auger assembly from a junked 1500 lb. per day, Scotsman ice flaker. Replace the shaft seal with a high temp B&G stainless pump seal. Replace both bearings with Fafnir sealed high temp ones. You'll need to have the shaft and auger barrel milled to accept the seal. The inlet and outlet of the assembly is 2". You'll need to weld a couple of stainless flanges on the ports. You can chop off the refrigerant pipes as you'll not be using that part of the auger. The pipes can be used to fashion a toilet paper roller or wind chimes. Then, bugger up your "pot" with some 2", 4 or 8 bolt stainless flanges and bolt the auger to it. You'll need to replace the drive motor with a reversible motor. The entire assembly weighs about 200 lbs. You may be under 1.5 grand when it's all done. A peristaltic will move mash. One with big enough ports isn't cheap. I tri-decoction everything I brew. My grain bill is only 20-25 lb. I use a 15 gallon tri-clad on a burner, for a mash tun. I use a stainless pitcher to move the mash to a 5 gallon tri-clad decoction kettle or to the lautertun. It's not all that bad. But, I'm not in the big league using a 500 pound grain bill.