I've used Lane regs on both my 400 and HFT500 (which has exactly the same internals as the 400) both carbined from standard lengths. It does take a lot of testing using different combinations of valve spring tension, hammer and hammer spring lengths and strengths to get it bob on on an Air Arms so it can cost you to get it done right by someone else, Lane says on one of his downloads he charges £250 to set an Air Arms up because of all the testing. I made different weight and nose length hammers, had different length/strength springs, spacers etc to mix and match to get it right but now well happy with 120 shot 775fps avg from a carbine 200 bar fill. Heard good things about the Huma reg as well.
Don't know who does a full,proper set up, know of some "tuners" that are happy with 80 shots from a carbine but they are obviously wasting air somewhere along the line, the MPR should be nearing 200 shots with a regged standard cylinder.