I'm considering installing Poly/Alum doors on the front of my 5 SS bays to save on utilities. I have 2 year old cheap metal doors on the exit side. Has anyone used the Poly doors sold by Menards? My intention would be to lock and seal 2 or 3 bays during cold weather. Should I install operators to increase the possibility of customers closing the door when they leave? Can anyone recommend doors they are happy with? I am using Airlift on my automatic but they're pricey.