Trying to find out which mirrors to purchase, my truck came without the tow mirrors but was told it is wired already for the tow type extendables. When I went to the parts dept, they were asking me if I wanted the heated with turn signal or non heated type. Truck is LT1 package, and removing the sail & door panels I do see the wiring, just not sure what level of control it supports. Anyone know how to tell to buy the right ones? Thanks.