You can get the monitor through the Blood Pressure Association here http://bpassoc-shop.org.uk/
Its under the home monitors tab!
Currently they are retailing at £59.99 but they can also be used by people who are not pregnant so good for partners etc too!!!
I hope this helps.
Good luck with the referral, let me know if I can help at all.
Every Woman is entitled to understand what happened in her pregnancy when pre eclampsia strikes. I hope to be able to support that process.