Have you considered Lutron Radio RA2? They keypads are a bit better,.. but if they keypads are all hidden (panelized-like) it may not matter. Can you just stuff the keypads all in a closet somewhere?

What if you put it all in a big box, like a hoffman 20x20x8 (or whatever it needs to be) and have a cover plate fabricated to standard gang sizes so it could hold the switches?

Edit-- I see that is essentially what was linked above.