I shoot a Browning 425 O/U. I have probably put 10 to 15 thousand rounds through it in the last 10 or 12 years. Used to shoot somewhat competitively, and with leagues and practice, I was shooting about 200 to 250 shells per week.
The choke selection really depends on the station and course, however, I usually shot most of the courses I have shot with a Skeet and an Improved choke. Unless you are shooting a tournament, most of the courses are set up so you can shoot them with fairly open chokes.
I know most of the manufacturers don't want you to do it, but occasionally, I would shoot with no choke in at all. I just cleaned it really well, and I was good to go.
We have a SC course just south of Russell that I helped develop when I was a banker--the shots can range from 10 yards to 60 because of the terrain. I tend to bring more chokes along than I need to--better to have them and not need them, than need them and not have them!
Have fun!
Tim