I've been looking into dropper posts recently and think I've narrowed it down to the Thompson or KS Lev. I emailed KS to see what was happening about UK distributor as warranty would be important to me. Had this reply:
We are currently in the process of finalizing new distribution for the UK.
At present we are not able to mention the distributor by name, but they are a great step forward in our ability to better service the UK market.
Sounds interesting and promising...