I was speaking the the importer yesterday and he said he tries to keep one of everything in stock, as deliveries from the factory can be somewhat problematic, so, first, there are not too many examples sitting in dealers shops and second most of the gun porn examples are not factory rifles, but are 10m Match rifles that have passed through the hands of Jon Harris, the master of conversion.
There are one or two factory made full power versions about, I have one, a Basic FT in the beech stock, so far it seems like a super little rifle, but there have been examples of the metal stocked 800x suffering measurable point of impact shift. Jon can sort this, but it is additional cost.
So, to a degree, the availability of at least the 800x is down to how many Jon can convert.
"I'm your huckleberry, that's just my game"