No matter what gutter system you go with, I think you'll really want the snow jacks. My neighbor has a metal roof on his work building, and he put them on after the first winter. 1) Sliding snow/ice really hits the ground hard, and he had a car damaged. 2) The sliding snow and ice is really, really noisy. You might bet woke up at night by it. 3) Safety feature - if a car can be damaged, just think what it could do to a person.
