Oh, yes, mountain flying in the UK. You must be kidding.
If I get that right, your highest mountain is 1344m. In Switzerland only landings above 1100m qualify as mountain landings and that is still pretty low, even for a Robi or a Schweizer/Hughes.
For the Robinson haters. I have flown quite a bit with Robinsons in the mountains. It isn't a problem, as long as you know what you are doing. Stay within the limits, which is the same for any helicopter. In a Robi you can still hover in Big Bear on a warm day with almost half the fuel and two on board.
Ok, that was with an Alpha. Wasn't as heavy as the Beta.
The R22 is certainly more difficult to control in windy situations, but in that case you just don't go. But they are not unsafe.
Sure, if you want to be working comfortable in the mountains, there is no way around a Lama or a B3.