The cab I have been building has the CP at about 960mm. It is a low boy style though. 960 feels fine to me. I think as long as it's not crazy high or low, the exact height isn't critical. after all, when you think of the old arcades, they had people coming in from say 10 years old up into their 20's that's quite a range of human heights, all happy to play on the same size cab (",)