Twenty-five feet isn't all that high, especially with a cherry picker. What you're trying to do with mounting a heavy PTZ from inside is like re-inventing the wheel as a square object. The next suggestion is to get a professional to install it for you, at least the mounting portion.
From the Amazon listing, this camera weighs 1lb but is a PTZ. Not really heavy. I've had professionals out to install the larger, heavier PTZ. That did not go very well.