Happy to oblige... gunnel is a derivative of the word "gunwale", a term for the kayak's top rail. It's commonly used to describe the upper edge of the side of a boat. My apologies for any confusion.
Regarding the storage method:
I used the wall brackets topped by 2x4's. The wall brackets have three or four screw holes in their top edge which I used plain 'ol drywall screws inserted from the underside of the bracket into the underside of the 2x4 just to hold it in place. The hose clamp at the rear provides needed insurance of securing the cantilevered 2x4 onto the bracket. The 2x4's I used were cut to 32" specifically for an Outback. The vertical standards were screwed to the studs with several 3" long deck screws. I tested each bracket by hanging my 185 lbs on it before entrusting my Outback to this storage solution. I bought the standards and brackets from one of the big box home improvement stores. Hope this helps.
Shows vertical "standards" screwed to studs.
Shows bracket with longer 2x4 with carpet padding stapled on top for protection.