While putting the parts list together I saw where the Yamaha PX5 amp has a power boost mode that is similar to what other amps call bridging.

Figure that if I use four 4520 cabinets I can set the amps in power boost which will give up to 1400 watts at 4 ohms, although with the two drivers in a cabinet in parallel the maximum I can feed the drivers will be 1000 watts. That should give plenty of headroom.

I can then maybe use Yamaha PX3 amps for the midbass and treble drivers.

Concerning the 4520 cabinets should I just run the wiring out of the cabinets or is it ok to install a terminal plate with a speakon jack on it?

What concerns me about that is power handling.

Would the jacks be good enough or will a direct wire of the drivers to the amp be best long term?