Hi Gav...that is one hell of a question.
HFT scopes are harder to suit than FT scopes. There are so many variables.
I've used MTC Vipers for years and are great for the money but if you look at the national HFT series and look at the scopes used by the top 20 then you'll see at least 10 different scopes. I have owned almost every HFT scope over the years in the search for the holy grail.
For example i paid 750 quid for a Leup MK4 and thought it was awesome on the zero range. Then you get on a course and find that you are missing more targets than normal as (for me) it suffered huge parallax error, same with the TAC30 and Bushnell 4200.
Can you get to Emley this sat morning as there is an open shoot on. There will be loads of different HFT scopes there and you'll be able to check them out. You could come along for a shoot too.