Originally Posted by jw131313
....which is in another room.
HOME THEATER - high ceiling room, screen against windows, see attached image
5.1 in-ceiling speaker system (but the sub will be wired and sit on the floor)
XYScren - Projector screen
All advice is much appreciated.
I guess my first advice would be to NOT use in-ceiling speakers if at all avoidable. In-wall or surface mount speakers would be a much (MUCH) better choice for good audio. This is covered over and over again. If you've already heard this, and don't care, then that's up to you. But, maybe consider adding wiring for at least front wall speakers in the future. Remember, half your audio will go UPWARD into other rooms (if there are any) from ceiling speakers.
You are running CONDUIT to the projector correct? 1.25" or larger flexible conduit is the ONLY way to protect yourself from when technology changes. HDMI 2.0 vs. HDMI 2.1 being a good example. Multiple people having issues with 18Gb/s HDMI cables is another example.
If you want to have something at the front of the room, near the screen, at some point in the future, I would run a cat-5e or cat-6 cable behind the screen location to the equipment closet. If you never use it, who cares, but if you do use it, then it could be for an IR repeater, or a USB3.0 extender (XBox camera) or something else if you want/need it.
Likewise, you should run a category cable to the projector. But, if you run conduit (like you should), then you can add whatever cables you want later on to the projector location.
I balk mostly at the in-ceiling speakers. They are really detrimental to a quality home theater setup. Fine for a few years, but at some point, you will want good speakers in there I would imagine.