BJ -
I put home-made rod organizers in both my boats and anchored them with screws. There isn't any real strain on them so you won't need long ones. I think I used #10 or #8 stainless that were 3/8" long - just enough to go through the carpeting and into the base of the locker/cap.
As always, I coated the threads with silicone to keep the screws from backing out.
me!