Bumpage? Is it a fairly easy job to trim spokes down to size and re-thread the ends? The bloke i was going to get to build up my wheels says it weakens the spokes??
It would be fairly easy if you have the right tools albeit still very time consuming.
Your wheel builder is correct in what he's saying IF you are thinking of getting a thread die and recutting the threads on all the spokes.
The threads on spokes are rolled on, therefore keeping the strength as nothing has been taken away. The tooling for that is expensive and not something you'd buy for one use. As different size spokes are generally available to buy not many wheel builders buy the tool.
I think your easiest/cheapest option (if you are unable to get 'off the shelf' gold spokes in your size) would be to get regular spokes and paint them with coloured lacquer spray, you may need to use a hardener as well and be very careful when fitting/tightening.
Good luck