Establishing correct tyre pressures with diffent size tyres

[The AJP Griff]

Ive fitted different size wheels and tyres to my Griff and would like to find the correct pressures to run them at.I have taken temperatures accross the tyre profile but with the negative camber im running there is quite a difference from one side to the other and an even temp all accross is impossible.
How do I arrive at the best pressures? As the negative camber will allways run the inside edge hotter should I be looking for the minimum discrepancy possible accross the width? Or should I set the wheels with zero camber to measure temps then re-set camber afterwards?
I'm guessing that finding the least discrepancy with the camber already set is probably correct but I cant find any reference to measuring the temps and taking into account the obvious effect the negative camber will have.