I have one from Omnipole. £2500+VAT. 1day to fit in London by Omnipole. I use mine quite regularly on new jobs and difficult cleans. Water heats to 60 degrees on demand and has a safety cut out device if it gets too hot. It's diesel and average running costs are similar to Ionics version.
Kev R, you're welcome to have a look when we next bump into each other.