Well, I just use whatever hat happens to be on top of my balding head at the time, but lately it's been a black and grey UofU ball cap.
As for the brisket, I just go with a simple rub of kosher salt and fresh CBP. Sometimes I'll just use some Monteral Steak seasoning as it has some other good spices in it.
I've only injected one brisket flat only because it had no fat on it at all. Aftering injecting it with some low sodium beef broth, I laid out some really fatty bacon strips over the top so it wouldn't dry out too much while in the smoker.