Neil,
I had the same thought a few weeks back. There is a thread on here somewhere. In short, I found a few on Ebay that state that they will fit the Lee/Hitech holders. I took the Hitech to mean Formatt Hitech, duly ordered one, only to find, to my dissapointment, that it was to big by around 3-4mm. I think that the suggestion that the ring adapter would fit Hitech may mean that it's for the Lacroit system, or perhaps something else, as it certainly would not fit my 100mm system. I sent mine back for a full refund.
It's rather a shame that a company like Formatt Hitech charge such an extortionate amount for something so seemingly cheap and easy to make. The ebay one I bought was £13 and even though it's the wrong size, it would be the same sort of production costs. If they can do it then I'm guessing that Formatt could, too. After all, if you are buying an adapter then it's a fair guess you are already an exisiting loyal customer. But then again, perhaps they feel that as you are already tied into their system then it's time to get pulling on the udders and milk you for as much as they can.
If you do happen to find an 82mm wide angle adapter that fits I'd appreciate if you could let me know.