Just to clarify, are you looking for an A/V "consultant" or are you asking for our advice? I've done plenty of home theater set ups for myself, from large projection systems using old 3 gun CRTs to more modern types, and did substantial sound systems with them, several using multiple tube amps.
Though I'm very much about tubes in my two channel audio systems, they generate a lot of heat, and in my estimation, are unnecessary for home theater, unless you are planning to use some of that gear for audio only purposes. One bonus about home video is that there really was trickle down- when I started messing with high end video in the early '90s, it was beaucoup pricey for top tier gear. A Faroudja line doubler/quadrupler was close to 20k dollars, now it is a cheap chip you can find in a box store Blu player.
I'm not up to speed on the latest high end projection systems- when we moved, I got rid of all the projection stuff, racks and ancillaries- gave them to a few friends-- and installed a more modest system with a flat screen here, in a smaller abode. Great image in a dark room. I still use basic components, i.e. pre-pro, rather than AV receiver and basic multichannel power amp (a McI, as it happens) along with 5.1--with a Rhythmik subwoofer. I have not bothered to set up an Atmos system.
In my experience, most people used to upgrade their television systems before they crapped out, but for video, I'd be concerned about useful life, whether there are parts available (I remember replacing the bulb in one more modern unit back in the aughts) and I've encountered manufacturers of modern flat screens that do not stock critical replacement parts for stuff that is barely out of warranty.
So, I'd say you can more safely do the "audio for video" used, but look to new/demo with warranty for the display/projector from a reputable vendor.
It might also be valuable for you to see a few higher end set ups -- you are near enough to the D.C./Philly/NYC metroplex to find some high end dealers who would let you see a demo of their systems. A lot of money and profit can go into the accoutrements of the "theatre" aspect- construction of the inner shell, acoustics, seating, (and flooring if auditorium type seating), along with hiding the gear if you are after a certain aesthetic. That's also where consultants can make money.
Have fun.
