Red Wings. If you can find a local dealer, buy them there. They take very good care of you and the boots you buy, making sure of a good fit. Even oil them up, from time to time, for you. Any flaw in the workmanship, will replace with no questions asked.
A friend use to do heavy squat workouts in his army boots (Zipper on the sides airborne boots) and really liked them. Also regular GI issue boots would also be good for heavy squatting.