Some other things to consider regarding costs and quotes.
I just finished my private training here in the states. It cost me just under $25,000 all said and done. Keep in mind the quote you got sounds like it's based on the minimums required for a license and that's usually not the case. For example, here the minimum is 40 hours and I did it in 79 hours. This was because our school has extremely high standards to make the checkride a walk in the park(so to speak). It also depends on the type of aircraft you learn in. The R22 is going to be about the hardest to learn in and the Schweizer is a little easier. The R44 is a little easier yet(except slopes). I have friends that trained in the Schweizer at other schools and they still passed their checkride in about 60 hours. I also have friends here at my school that took 90+ hours to pass. So the quote is pretty much worthless because there are too many variables, the biggest being how proficient you are.
I would take the hourly rate for the R22 and finance at least 70 flight hours plus ground time.
I agree with them on the medical, get that done before you invest a single cent into flying.
As far as studying now, sure go ahead it wont hurt anything. It just may waste a bit of time if you can't get your medical so get that done ASAP.
As far as the aircraft and flying. I've flown the R22 and R44 and everyone I have talked to says if you can fly the 22 then you can fly anything. I'd recommend starting with the 22 and go from there unless you have excess money. Fly the 44 because you can afford it and because you WANT to fly it. Don't fly it thinking that it will make a difference in your flying capabilities for aircraft. Sure it will broaden your experience but it's not needed to be able to fly bigger ships.