You are quickly learning that people have different opinions on pulled pork. I will give you my experience on smoking butts in hopes that it helps. All smokes were at 235 F.
First - I didn't give it long enough and ended up slicing it. I learned from this to give it lots of time (I often smoke the day before and reheat).
Second - I started smoking over a mixture of apple and pecan (She Who Must Be Obeyed liked the lighter flavour). I foiled for the last half and didn't worry about time. At an internal temperature of 200 F, I started pushing a probe in. When it went in like it was butter, I took it out and wrapped it in foil and towels in a cooler for a couple of hours. I ended up with a moist delicious pulled pork with a delicious but soft bark.
Third - I smoked over a mixture of cherry and oak, I got an even lighter smoke flavour but nice. I did not foil and used the same test for doneness. I took it out and let it sit for an hour. I ended up with a delicious pulled pork that I thought was marginally drier than the foiled. However, it had a wonderful dark crispy bark.
What I have learned through this process is that it is a matter of taste. Now, I foil sometimes, some times I don't. I stay with the lighter flavoured woods. I prefer the without foil marginally, the missus prefers the foiled marginally.
I suggest you try both methods and pick the one you like better. You'll love them both.
As for type of wood, I find apple, cherry and oak are all nice.
Go forth. Experiment. Find what you like!