The vertical climb capability of a helicopter is not a figure you'll come by easily, I don't recall a performance chart that gave such information in any flight manual. Climb charts were available for climb at normal climb speed however, usually in the order of 60 or 75 knots for the helos I flew. The parameter you may be looking for which would give a similar answer is the helicopters out of ground effect hover capability (OGE), or the in ground effect hover capability (IGE). Go to the relevant manufacturers web site and they will give the relevant figures, plus the other info you seek.