WE used to have a couple of companies who could fit DPI’s a lot quicker and cheaper than National Grid, however they were stopped from doing this about a year ago. So, we are in the same position as you. I would happily pay for our Electricians to be trained by National Grid so we could install them. Until then we seem to be at the mercy of companies who are in no rush to attend.
If anyone does know of companies other than National Grid or Utility companies – please share. Perhaps we should start a campaign to allow us to fit them?