There is an abundance of quality cases out there. I have a couple of Browning polymer cases and a metal Americase. I've used Kalispell and another one as well, and believe the metal case makers have consolidated such the Americase absorbed Kalispell and someone else. One of them made cases for Cabela's back when, Cabela's still has a "Bullet Proof" case that will work fine. The important thing is to have good foam and lock them, and be there to deal with the TSA when they inspect them so you can ensure they are locked and wrapped in duct tape as a seal. IMO, it is better to have external locks in the event someone in midstream decides it it essential to enter your case and inspect your guns. If they cut a lock to inspect, it can be more easily replaced than an integrated lock built into the case.
Pelican cases are good as well.
I believe you will need at least a 36" breakdown case for semiautos because the components are longer when broken down than an O/U or SxS.