As to the size of the screen, you might consider a step-wise approach. Select and purchase the projector first, install it, and project the image onto the screen wall. You can then zoom the image to various sizes for final selection in your room. This is what I will be doing in my room to understand my entire range of screen size options and where the screen would rest on the wall.
I think the "Screens" forum would be best to pursue recomendations. I've owned both Stewart and Carada screens - thought they were both great for my application. You'll need to understand your application parameters (is the room fully light controlled, will you use it exclusively for theater, or with lights on too for television/gaming, color of room walls and carpet, frame style, etc.) as these can all affect your final choice(s).