I have a 1951 170A and love it! It is a great flyer. Great looks. A tame taildragger that you can see over the nose. The 170 Association is probably one of the best type clubs out there. The 170 is simple to work on and has very few AD's. There are a couple rights of passage in 170 maintenance (fuel tank selector valve is hard to get to and will some day leak, door latch springs will break but can be improved). Just like any 75 year old design, parts are not plentiful, but I really haven't had any trouble getting anything either. Word is O-300 cranks are hard to get if you need one, but there is also a company out there who recently has been increasing activity to keep O-300's going (Airworx LLC).
Sure the 170B flaps might let you land shorter than on a 170A, but unless you have more horsepower you can still land a 170A shorter than you can take off. Plus no flap tracks to wear out. I am based out of a 2500' grass strip (650' elevation) and it is a great performer there. No worries about getting out or getting stopped. So in my mind no huge need for the B model (unless you are going to upgrade engine, want to put on a leading edge STC, or add extended baggage). The one time every year I wish I had a B model is when I need to crawl in the back to inspect the tail cone because the A model has aileron cables going up the middle of the access to the tailcone where on the B it is wide open. But even my 250 lb frame can squeeze past it to lubricate the flight control pulleys.
It isn't going to break any speed records, but it is a very utilitarian plane. My wife and I have thrown mountain bikes and tons of luggage in the back. Plenty of room for camping supplies for two. Depending on the size of the people, you can take your wife and another couple to the nearby $100 hamburger.
There is also an active population of people replacing the O-300 with 180hp - 210hp motors. I can only imagine how well that plane would perform.
Other common upgrades include: larger tires, 180 gear legs, adding baggage doors, Rosen visors, door stewards, folding jump seats, thicker windshield with no center strap, tail pull handles, lightweight starters, and more.
I purchased a bit of a project plane and have put a lot of work into it. So just like any other 70 year old plane you might want to buy, get a good pre-buy inspection. Ideally by someone who knows the type.
Good luck!