The 160MHz carrier and it's ability to penetrate walls and go round corners is the magic that is going to be very hard to replace.
IMHO the NHS is big enough that it should be able to use bespoke products as their end user population for almost anything is large enough to generate economies of scale. If they were to take the opportunity to add some marginal improvements to the existing pager system then they would have a device that others with similar coverage issues would adopt.
Biting the hand that feeds IT
