like. projectorcentral.com is a good resource for deciding which projector you should get.

As far as screens go you can get a motorized drop down screen so the kids can’t mess with it when it is up. Or you can just go cheap. My screen is just a white blackout curtain stretched out over a frame that I built.

Of course you’ll have to think about speakers/receivers or a sound bar and something to run the whole system as well.