As an 'industry' guy, a couple of points. I have owned and sold both projectors & big plasmas & I am seriously biased.
Everybody wants a screen that is too big for their room. From your seating position, you should not have to move your head to see what is happening at the extreme edges of the picture.
The sound system is as important as the video system so think about spending equal dollars (or even more) on the audio. Dual subwoofers are good.
A good screen will maximum brightness - which is a good thing. The blacker the blacks, the better the color dynamics.
Led displays (or projectors) always have a 'video' look rather than a 'cinema' look. That's why plasma displays are often preferred - they give you cinema. You choose which one you can live with.
4k displays are stunning but most of your watching will not be 4k . . .
Ian