Full-sized multicopter mass v acceleration help

Singnome

I really feel like this is something i shouldnt be struggling with, but I am attempting to build a full-size multicopter, capable of a gross weight of 300kg.

I have calculated the power needed to achieve vertical thrust working on an effective total rotor area of 5.6m2

Because the system is based on differential thrust controlling movement along all axes, the motors must be responsive to input. The proposal is to use eight DC electric 7kw motors (continuous rating).

My goal is to maximise rotor diameter in order to maximise range (battery weight constraints apply).

What I need to work out is the relationship between the mass of the rotor blade and the torque required to accelerate it. Then I can create a spreadsheet and find the point that i'm happy with.

Thankyou very much for any of your time

Louis