I want to wall mount my front stage under a large screen (120+"). What would be better, three Supersats along the bottom all mounted horizontally, or the Cinema array??

With three identical I would worry about comb filtering/crosstalk.

With the single array, I would worry about lack of separation given the big screen.

Plan to use two subs, room is large about 16 x 32 x 9

No idea, but just wanted to mention I believe Goldenear is releasing a larger version of their sound bar called 3D Array XL I think, this might be something that would interest you with this large screen....

The deciding factor is listening distance. If you cannot separate the L/R speakers equivalent to your seating distance (or more) the 3D Array is the better choice as it will give you an appropriately large soundstage that will be missing from the too closely spaced SuperSats.

Hope this helps.