If your still open to suggestions, get the 18' barrel for your mossy and use it.
It comes with the right choke for skeet, cyl. shoot it for a while decide if you even like skeet first. The gun will surprise you, how well it works, and its truly satisfying whippin the pants off of shotgun snobs. Added benefit your mossy becomes slick as glass, and you become rattler fast with your HD gun!
Back when skeet was invented ever one used pump field guns with the barrels sawed off to 24"! A Mossberg 835 is my sporting clays gun. 2 years ago I was at a benefit shoot for the Arthritis Foundation,when we were on the back 9, torrential cloudburst! I watched guys, poor rain water out of the barrels of some really expensive guns . One was a Beretta DT! I just shook off the mossy and threw it in the trunk.
Missed it that you bought the Lanber, they're a real sleeper for the money, as for O/U vs. repeater. the OU stays cleanest in the action,and never has powderfouling, O-ring, Plug gas port, galled parts type troubles. They clean up alot faster also. CDNN has Lanber tubes for $9.99!