What endless is talking about isn't "home-made" plating, but a job done by the Mint itself. It's an Australian thing.
Generally, the RAM doesn't do "special orders" for the privileged few individuals. Occasionally, they will produce a special product for certain associations they deem to be worthy (such as ANDA or the Royal Society of Victoria) or choose to select a sole distributor for a certain product (such as the Commonwealth Bank or Downies). I don't know if the company or organization in question pays for this privilege.
The Mint won't plate for you a coin in your collection that they've already sold to you. If you want one of your own coins plated, you'll have to get it done unofficially... and I should also point out that in Australia, doing so is illegal.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis