Well IMHO you dont have to foil at all. For me the 2 main reasons to foil are 1) to get a desired color on the bark (foil stops the bark from getting too dark) and 2) to help to get meat through the "stall" if it's giving trouble. Generally I dont foil. And there are downsides to it as well. You lose some of those signature bark characteristics that you get when you dont foil as well as if you foil for too long the meat can run the risk of being too mushy.
However to answer your questions, I generally foil butts at 160 and brisket about the same. As far as wood flavor, beef can take a stonger flavor smoke than pork generally but you dont want to overpower the pork, so a medium bodied smoke like oak or pecan will work great for you. Again it all depends on your tastes and what you like. Experiment my friend, have fun with it.
Cheers
