The passport 41 was a later iteration of the 40 and I believe that less boats were made to this design. The major difference is the stern which has already been discussed.
Regarding putting a wind vane on this type of stern, it has been done to a 41 before so I would not expect it to be a problem. You can see one example here Scanmar International
I have never been fortunate enough to actually be underway on one but sailing next to them and being aboard at the dock, I have really been impressed. While you can't get your heart set on one boat or model (especially if there were not many made), I would definitely keep this on my list of boats to look at given your criteria.