Just went to my local music store in Lausanne, Switz and saw a new line of soft trumpet cases by Ritter. Check them out, I like the 'classic' three trumpet case that will go on the plane and looks like would also hold enough clothes for a two day trip if you had just two horns packed inside. Special place for a foldable lyre too. It has very top of the line zippers too.
www.ritter-bags.com