Do you want the cab mostly for summer or winter comfort? If summer, then I suggest you go with a good canopy which is nearly as effective for comfort under the hot sun and has the following advantages over a cab: much lower cost, ease of removal for overhead clearance or forrest use, less obstructed view, No hp consumption (AC), compatibility with backhoe, lower center of gravity, less expensive to maintain. No help in the winter unfortunately. Also, I understand your preference for the PR trans. I also had a hydro once and I like the PR a lot better. It is nice to have the ability to put almost all of your power to the ground without the losses associated with a hydro. Hydros have their place for lawnmowing and loader work, but not for ground engaging tasks which I do much of. I also like the PR in the cold winter as you dont notice the difference in performance when it is way below zero, or 100 degrees outside. Hydros can be sluggish in the cold. You have a heck of a tractor in that 4120, open station, PR. I have not had any issues in (4) years of hard use with mine.