While this is up to you, and very budget dependent, the ones I have seen can't approach this as UHD full color is 12-bit, so having 16-bit color would be wasted on the highest level of the current video standards. 12-bit per color processing would be the max that any display should need to work with. Total color support may be listed as 36-bit.
Yes, brightness is adjustable.
Price is typically just really high though.
At 98" I would get this:https://www.necdisplay.com/p/displays/x981uhd-2-r
At under $10,000 for a 98" NEC 4K display anyone on the face of the earth would be hard pressed to beat that price for the size with any technology that isn't front projection.
Now, I've seen LED direct view from a few manufacturers, and the results have been rather poor for recreating standard movies. I watched the Super Bowl on a 33' wide 4K LED video wall that I had been part of installing inside a conference room. I've seen these things, and they just don't measure up to the video quality that I've seen from flat panel displays and front projection.
Still, for what they were used for, they were spectacular, and I certainly like them more than multi-tile video walls or front projection in a lit room.
But, man... That NEC is a great deal right now.
- Theater, whole house audio, and technology consultation during the build and installation process in the Washington, DC metropolitan area.