What is your end goal? If you're thinking about ever going commercial (and having a 20 year career at a pilot ahead of you) then definitely get a class one medical sooner rather than later.
As for flying, go for the PA28 - it's not expensive but will save you money in the long run.
As others have said - it takes as long as it takes: if you are getting into flying as a hobby, you'll continue flying after your PPL, so hours don't matter. If you're getting a PPL as a stepping stone to a CPL, you'll still need to build hours afterwards, so again (to a point) hours don't matter. The number of hours for your PPL is a matter of ego only.
With that said, and not wanting to start any arguments - it should be easy to get a PPL in 45 hours if you follow some simple rules (which you won't!):
1. Get the exams out of the way before you go flying. With them out of the way you can have an uninterrupted course of flying with only weather and maintenance getting in the way. You want to be flying 5 times a week if possible. So do it in summer. Or Florida.
2. Learn everything about the aircraft before you get in it. Know the POH and checklists off by heart and when you need them.
3. Don't plan on learning anything in the aircraft - you should get in knowing what you're going to be doing. That's where a good brief is with its weight in gold. Use the time in the aircraft to watch the demo then practice, that's all your brain will have capacity to do.
4. Chair-fly every day. This is the best piece of advice you'll ever get and it's free. Your instructor is simply looking for you to demonstrate competency in each maneuver: if you forget to put the carb heat on, or do a checklist on downwind - you'll have to do that maneuver again. You give yourself the best chance of getting it right sooner if you chair fly and turn up prepared.
5. Learn in a 4 seater. Pick a buddy to learn with and back-seat as many of each others flights as you can.
You will learn as much if not more from the back seat watching someone else struggle as you will from the front - because the pressure is off and you have spare capacity. You'll have much more exposure to radio calls, traffic patterns and especially navigation and area familiarity. For free.