I use a ridgid 18v compact. It has about 550in/lbs of torque and I have the 4ah batteries. It works fine pulling right through the ice all day with a 6" ht auger. I've heard nothing but good about the nils augers with the drills except that you need a special adapter for the clam plate. I want to try an 8" nils on mine. I don't know where you get that you need 1250 in/lbs of torque for a 6" auger.
The clam plate works great, I have the older style and I made a simple adapter for it that lets me use my drill without taking off the chuck. Works fine. I like the plate because it makes the whole thing feel like a complete unit and not something I cobbed together in the garage.