Buying a plane....buying a glider. Back to the original question. First aircraft I ever bought was a Pegasus glider, that was after doing a lot of cross country flying in K8's and K18. I didn't like the single seat Astir at Booker gliding club, wasn't comfortable in it, I just didn't fly it very well, it was heavy and quite different from the wooden gliders. The club then bought a couple of new Pegasus gliders, one fixed wheel, the other was retractable. WOW, what a difference! I was COMFORTABLE IN THE SEAT. And the performance, with a glide ratio of 40 to one, was excellent, the handling delightful, the airbrakes EXTREMELY effective, so I felt confident in landing out.
So, before deciding what airplane to buy, try to fly as many different types as you can arrange.
And be sure you are comfortable in the seat. Though I hope with pax you would think of their comfort and make a stop every 2 or 3 hours. (In the glider, the Peg, my longest flight in the UK was 8 hours and 53 minutes, I was busy the WHOLE TIME! flying 511 k in a competition.)
There are plenty of 4 seat aircraft for you to try out. Sit in them. Try out the back seats as well. ( You will have to be firm about luggage. Remember weight and balance really matter.)
Fly them. Check out the airfields near you, what will be the best place to keep it? Consider shares. Nobody sails a yacht 24/7. Mostly they sit around in marinas. So shares make sense.
Speaking as an old granny, I am trying to talk a friend of mine who owns an interesting aeroplane to take me with him for an excursion to Italy. The crunch time follows when I try to climb into the aircraft. And likewise, try to climb out, it ain't easy these days. Took three people to install me in the club Chipmunk, two to push and the pilot to pull. and I am NOT FAT. Just old.
So if you might actually take your mother up some day to fly over her house, this might be a factor....how easy for your family to climb on board?
All you experts reading this, is it possible/legal, for passengers to change seats in flight?