Projector TV seems to limit where the screen goes a bit. Or where the projector is. Make sure the centerline of the screen is at eye level because you don't want to have to look UP to see the screen like those installed over a fireplace. Bad for your spine, especially your neck.
Re: screen size, a really large screen is what you'll need if you want to be able to have up to 8 people viewing without a tiered floor in the room (4 seats on front row and 4 behind, up about a foot).
When I'm watching a movie late at night by myself, I turn off all the lights and pull a chair right up to about 3-4 feet away from our HUGE 40" Samsung and it's like being in a movie theatre.
Re: the brand you pick, I've always heard go with one of the top 3 or 4 most respected and stay away from the lesser/store brands and you'll be happier with quality and longevity.