Just did this on mine minus the bracket. There's really no need for a bracket. I just used two zip ties to attach it to the fender and two to attach the triangular base to the original mounting location. I'll have to look for an Escalade replacement piece, but you'd have to be right up on the truck to notice the small hole for the stock antennae location, so no biggie.
Oh, and all I listen to is CD's or XM anyway, so no big concern about if I lost any stations.