Been pretty happy with the home-made rig so far. GPS mounts to the top, and headlight/bilge pump etc controlled from the switch panel mounted to the strut.
I am in the process of having a buddy who can weld like no one i have ever seen build me one. I have a pedestal seat base toward teh back of the boat. Thinking bout havin him weld me up a "T" handle and machine the base down so i can insert it into the pedestal base. Then once i am at the spot take out and store.
Here is another style. I made this one, It folds down if I need it too. Attaches through the box down to the floor.