Eomer, can't imagine how much a 90" tv would cost, why not go with a projector ? My crappy Optoma hd72 does an amazing job on a 100" screen.
I've been running a projector for 8 years or so, on a 106" screen. First an Hitachi PJTX-100 (or something like that), and a Panasonic PTAE-2000U (again, close enough) the past few years. I've had bad luck with both in terms of image quality issues. The panel has shit out on both within a year or two, with blemishes, burn-in, and flickering. Also I don't have great light control in my place, as it's a condo with very large windows. Finally, I can't use my TV if it's windy, as the PJ is mounted to the ceiling, and I live in a 100 year old brick and timber building where the roof will flex up and down under high winds, causing the whole picture to sway around. Also, there's probably a high rise going in 20 feet from my place across the alley within the next couple years, and if they do any piling it'll be the same thing until they're done.
I'm just kind of sick of projectors, given the problems I've had with the panels shitting out, not to mention replacing bulbs and the like. The current bulb is probably good for another 3-6 months, at which point I'll be replacing the projector either with a new one, or an actual TV. I'm just trying to decide which. Sharp has a 90" that's going for around 10k, which is definitely on the expensive side, but between the two crapped out projectors, the screen and replacement bulbs I'm easily at 6-7k with projectors.
Maybe third time will be a charm if I go with another projector and the panel won't crap out. I'll likely take the current Panasonic in to a repair shop, if only to have it looked at to determine why the panel crapped out. There's blotches all over the place on it.