Sadly I know nothing about Atmos. I can’t help you there. I do know a tiny bit about some of the other stuff. You didn’t mention much about a subwoofer. I feel that they are just as important as the other components you have mentioned. You don’t want your sub being the weakest link. Having all your drivers timbre matched is a really nice touch if you can pull it off. By using the same tweeter in all of your speakers the treble parts will have the same acoustic signature (terminology?). If you have a ribbon in one, a horn in another, and some metallic domes on others it probably won’t have a cohesive feel. In addition, if you choose the same tweeter you MIGHT be able to get away with using the same crossover for all of your speakers.
As for as screens and projectors, I’m ignorant on that as well. Sorry. Good luck with your build. I feel the need to warn you that DIY is highly addictive. I can send pictures of my shop if you don’t believe me.