Thanks for the replies guys!

How loud is one of these silent generators? I don't really understand Db. I can hire a 6500W Honda silenced generator for a decent price but I'm scared it will be too loud, especially at night. And that I will have to have it a similar distance away anyway therefore having a distance problem again.

Would I be able to get away with a 2.5mm or 4mm cord per circuit? And at the end of this would I be able to connect an RCD to then distribute to multiple lights?

The boost-buck transformer sounds promising but I wouldn't know where to get one or how to use it. Also, what is a PVC raceway?