Question about PM07

Hello all. Im at he my last year in university and the final project Im making is a drone that flyes inside a greenhouse and collect data like temperature, humidity, etc…

Im gonna use a S500 frame:®-Quadcopter-Stretch-Versión-aterrizaje/dp/B01N0AX1MZ

Im using the Pixhawk 4. This one:ón/dp/B07CHQ7SZ4

For power management, i have been thinkig about using the PM07. However, it is build for Holybro Pixhawk 4, and that is not in stock. The only one I have found is the one i sent you de link.

My question is if im gonna be able to connect the PM07 to the old Pixhawk 4. If not, What power distributor could i use to power the becs?

Also, if you got experience building drones this size, what motor and propeller size do you recomend me? Im thinking about using a 6s battery to get more flight time.

Thanks to all