There is or was a place near Stockport that specialised in auto boxes. I have had autos in everything except bikes since 1978, coppers didn’t like me using a walking stick for one pedal in manuals, would t accept it was a ha d control lol.
My van is a Sprinter base with the six speed sprintshift ambulance box. Was told by someone it was the one to get if you have the option but don’t know if there is any truth in that.
To be honest I had the van almost 2 years before I found you can put it in gear when you park up and it hold it on hills. Never had that before on any auto or semi auto. Not used the van in manual so can’t say how good it is, on any auto I find it smoother letting it do changes itself. I have never had flappy paddles with two or three clutches though, only single. If I get a need I will try the manual on downhills and see how it does but to be honest it’s been fine in auto. May be because it’s got 6 speeds and not 5?