I use a 12 volt Dewalt and 6 in. lazer, made my own adapter, peice of conduit, place a nut inside so I could braze in a piece of allen wrench. Works great.
Don't forget to take a plastic bucket and cut a circle out to lid or bottom larger than the hole you will be cutting. Place that on the shaft so if the auger adapter comes loose from the drill chuck you won't loose the auger down the drink.
Gibby:)