Wanted to offer some advice on installing ray's brackets >>> don't overtighten the stainless button head bolt.
If you do, the top of the bracket will start moving away from the van because the 'z' piece that installs in the gutter will start pushing out on the vertical bracket.
I installed all of my stainless bolts to 90-95 in-lbs and bent the brackets in a vice to achieve a 1-degree angle from vertical.
With the plate mount attaching the bracket to the body, the load is spread over a much greater area without sacrificing sheet metal integrity with a hole.
Here are stock fiamma brackets for mounting to a vertical surface - the little lip that is a stepped offset rests in the recess at the top of the awning and the other end supports the bottom of the awning. the large flat surface sits flush with the back of the awning.