With the bolt on ball you need the Alko ball but detachable and swan neck are all OKI have used a Witter and a Brink (which is the same as Towsure) and they both did the job OK
There doesn't seem to be any data as to actual tow ball heights for different makes but I felt that the Witter was slightly higher but then they changed the bumper after the facelift.
Sorry haven't tried the detachble which I was glad about when I reversed into a tree !!!