After tinkering around with more posterboard models in multiple locations and configurations, I decided upon having two relay decks, one for each side. I am able to keep the wiring bundles for the stick grips small and neat, plus am able to gain easy access for maintenance.
I fabricated the two decks from stock aluminum sheet and angle. I cleco'd the decks into place after drilling the adjoining ribs. Once eveything was ready for install, I removed the decks and primed them.
I cleco'd them back into place and started wiring the sticks in (pic 2). I continued wiring the sticks and relized that I hadn't riveted the decks into place. So, I riveted the decks and completed the installs also installed the relays for both the pilot and copilot sticks--didn't take a picture when completed though.