Tyron bands, you hear a lot about them from those that 'have a mate who says .........'. All I will say is talk to those that use them. I've had two blow-outs in my 30 odd years of caravanning. The first was many years ago at about 20 mph on a B road. No tyron bands fitted, but not too much of a problem as I was able to pull up quickly and was only a very short distance from a save place change the wheel. The second time was a little different, 5-30pm, 60mph in the centre lane of the M27. Not exactly the best of places but once again no problem, I had tyron bands fitted. Would it have been the same without them? Obviously I cannot say for certain, but I feel a lot happier with them.
You often hear stories about problems in getting the tyres changed, but never from the person who had the problem. I've never had a problem, & I know people who have had them changed on the continent without a problem. If there are tyre dealers out there that 'will not touch a wheel with either tyron bands or have used sealant goo', I think that they'll soon be out of business judging by the number of cars now that do not have a spare wheel, only a can a 'instant (temporary) repair sealant.' As for 'run flat tyres', have you any idea of what they cost? I can assure you that you're talking in hundreds, & not the low hundreds either!
Finally Gaz congratulations in getting yourself a great van, far superior to these mass produced things most put up with. I will put my hand up to being a little biased, I also have an Accolade!