"So if we supply a fully painted wheel will the re-rubbering process damage it?"
The re-rubbering process will not damage the paint provided the paint is well cured (a few weeks old).
If you are going to repaint the steering wheel make sure the entire rim and the ends of the spokes are bare metal.
These areas will be painted with a special bonding agent that will help the rubber bond to the metal. I will make more specific details about this very soon before you go ahead with the painting.
"I'm on to a good powdercoater here in Perth, would that be a good base for you to work with?...."
Powder coating is fine as long as it is painted over bare metal and painted as described above.
"although Burton's gets the credit."
I haven't seen the mention. It seems to always be the way.....someone does all the work, and takes all the risks, but someone else gets all the credit.