Back from business trip, here are the holes dimentions:

15.25 deep (i can remove the drywall to add another 0.5inch)
8.75 wide (again i can remove the drywall on each side to ad 1.0inch)
38.25 height (i can remove the drywall and the upper 2x4 structure to accomodate the M60 in cab)

so i think that my final conclusion is that i will go with the M60 in cab, the VP150 in/on wall, the QS8 and the EP 500.

I will probably get a set of M3 outdoor at the same time.

thanks you all for your help!