You are probably getting a picture here that "It depends." If you are sharp and have good skill, head down and fly a lot each week, 40 hours can get you there. On the other hand, there are students who are clocking their 150th hour on the hobbs. The latter can be chauked up to a lot of varying factors including work and home life, skill, learning ability, type of school (61 vs 141), money, etc.
Flying one hour a week or 3 hours a month just won't get you there as fast as 4-6 hours a week for 6 weeks. The money and time it costs depends on how involved you are. If you do not take it home with you, read and prepare, and only wait until the day of your next lesson, it will take you longer.
Save your money, get enough in the bank to fly more often, then commit the time and do it in a couple of months. By the way, just because a lot of pilots take the winter off, most planes have fine heaters. Except for weather, you can fly all year long. There's nothing holding you back from studying.
You do not need a headset if the school has them. The flying books can all be downloaded from the FAA. Ground school is not needed IF you study. The medical will vary as will the FAA practical.