Ok. I will look into getting some 10mm2 cables made up for me, but I'm assuming they'll be expensive.
The most powerful light I will be running will be 2000W, but mostly 1ks and a few other incandescents.
So instead of having an RCD at the end of the cable run could I just have a power board of some sort? So I can run a few lights per cable.
In terms of the generator, a low hum sounds like it could be dealt with. I have a rental company near me so I will also check out some of their silent generators.