This plan sounds very well thought out! I especially like the catwalk system and moveable lighting rigs ala Steve Weast's tank. The "hospital is also a great idea". I would make sure that there is enough room for a workbench, refrigerator/freezer, sink, toilet (for all the skimmate), and a good sized blender or food processor.
Regarding skimmers, Deltecs and Bubble Kings are great and would be beneficial to this system, but for the scope of this project, you and your boss would be better served going with a commerical grade skimmer. AW2 recommended ETSS commercial skimmers which are great, but also take a look at RK2 commerical skimmers. They are ENORMOUS and can be optioned to included large ozonizers and even washdown systems to keep down on maintenance.
The shimmer of the MH will look very nice and should only benefit the tank. Pacific Garden Supply's Diamond Lumenarc 3 reflectors would be ideal for this setup as they cast a very large spread and minimize the number of MH fixtures that need to be used.
It sounds like there is also alot of professional planning going into this project, but if it hasn't been considered yet, I would recommend suggesting to the planners to "harness" the heat put off by this system to help heat the rest of the house. (I recently added a cold air return to my 300g's tank room that can be opened or closed to allow the heat of my tank room to be cycled through my HVAC system. So far this winter, my furnace has barely turned on, and that's saying alot considering we've already seen temps in the teens a few times here in Chicago. Hopefully, this will help my family save substantially on heating gas this winter; summer is a whole 'nother story!)
Anyways, best of luck with this system, and I can't wait to read updates as the project progresses!
:happyfish