So it’s called NoahLink Wireless and it’s made by a company called Himsa, a Danish company I believe.
But as an individual you can’t buy them in the UK as they are classed as a medical device. You might be able to get a professional to sell you one informally of course.
Alternatively you can buy from eBay and usually there are US or Asian sellers who are happy to supply. You will probably have to pay VAT and maybe duty as well when it’s imported, but you won’t have to do it again so I say just suck that up.
I bought mine from South Korea but if I were doing it again then I would probably focus on the US.
Good luck anyway.
EDIT: I see there are a couple of UK sellers in eBay who say they have it in stock. So that’s definitely the place to start!
SECOND EDIT: It’s worth checking that your new aids can be programmed wirelessly rather than just assuming. What are they exactly?