I suggest you get a rolling trunk for everything but the guitars, then strap the guitars on a dolley of some kind. As Leadfingers points out, it's important that the dolley (or dolley plus extension) be tall enough for you.

You can carry clothing in the trunk as well, and it will help pad the delicate items.

I have discovered that a bodhran filled with socks and undies takes up almost no room at all in a suitcase or trunk.