I was in the same boat in 12 gauge (running out of old Remington Hevi) and was advised to start with the Hevi 13. I set up my daughter's youth with a Remington full choke and Federal HW #7. Not sure if the Federal wad would be safe in a Comp choke, as I think they are all ported.
My daughter's is very sweet at 30 yards and in. I did not want an overly tight choke as I did not want her missing close birds. With your setup I would consider #6 or #7 Hevi. The #7 blew a 1x4 off the back of my target at 30 yards. Obliterated it in the center of the shot.