As far as shipping rifles i have a shotgun case, break down the rifle and slip the case into the pouch on my Cabela's luggage, viola! no seperation of luggage and gun case.
A couple of years ago I made a similar decision. I bought the Cabela's "guide series" rolling duffle and an aluminum shotgun case. Nothing makes me more nervous than shipping a case that literally screams "GUNS!!!" Slipping the shotgun case inside the duffel allows me to travel with relative impunity. It works for pistols, AR's, or hunting rifles.
On a different note, one guy I know travels with his guns in a beat-up Pelican case that looks more like a toolbox than a gun case. He stencilled "ACME SEPTIC SERVICE" on all 4 long sides in bright orange paint. Not even TSA messes with his case!