First: you dont need to shoot 3 1/2" to kill a turkey. I use 2 3/4" in my 12 guage. #6 cause it has more pellets. If you can get set up right and call them in they should be within 30 yards

Second: I just use a standard full choke because as mentioned above if you do it right they will be close and if they are real close you dont want to have too tight of a pattern. (I shot my bird last spring at 5 steps)

Third:you dont need to have a camo gun either. Some people use tape or what not but i never have and haven't had a problem.