You may have your wiring figured out already. I mounted a waterproof junction box on each of my manifolds. I had a hole in the manifold and the junction box had a hole in the bottom.
I then drilled the junction box sides and installed two Neutrik TLT4MP 4-pole Speakon connector. One is the OUT connector for both pairs of drivers and one is the IN connector for the drivers that had the wiring on the ouside of the box. My manifold has both outward and inward facing drivers so I have two drivers with wiring inside the box and two with wiring outside the box.
For the drivers with wires on the outside of the box I connected both drivers in parallel and then to a Speakon than inserted into the IN Speakon on the box. I wired the two drivers with wires in the box in parallel and to the OUT 4-pole connector. I also connected the IN Speakon to the OUT Speakon. Make sense? I bought some Dayton 13 gauge 4 conductor speaker wire and put a 4-pole Speakon on 1 end and 2 Speakons on the other end. I connected the single 4-pole to my OUT Speakon on the box. This allowed me to use one cable from one manifold to connect to two channels of my amp. I did the same with the other manifold.
You will have all your wiring on the outside of the boxes so it will be easier. However, you could run all 4 manifolds to 1 junction box and then use Dayton 8C wire to run from the junction box to your amps. Just use an 8-pole Speakon on the junction box and one end of the speaker cable and use four Speakons on the other end of the speaker cable for 4 channels of amplification. Or are you running each driver off a separate channel?