For a center, how about something like a pair of the FaitalPRO 8FE200 wired in series and then paired with the same horn and compression driver from the Cinema 10? Power handling will be on par as will the initial SPL.
No, I haven’t put any of this into WinISD or XSim, so this is just a hypothetical. Use a 1.5 CuFt box, interior dims. around 9″x34″x(+-)8″ and a 3″ equivalent port on each side, 2-3/4″ long will tune the ports to 69 Hz and an F3 of 63 Hz.