help choose AT Grey Projector Screen Size for Benq 2720i

[logu]

Hi,
Area: Dedicated Home Theatre

Wall Width: 10ft 4inch After Acoustics

Room Length: 24ft

Considering between 120, 130 and 135 inch screen.

Help choose one.

Am I right about grey AT screen for dark acoustically treated room?

How far from Screen should the projector be clamped to the ceiling?
How much ft from ceiling to mount?

Ceiling height before faux ceiling: 11 ft
After faux Ceiling: Little above 10 ft

Thanks!