That case Wickedartstudio has is exactly the sort of thing I wanted for a long while. I did get a Nanuk hard case once, but had to return it due to a bad gasket, and haven't gotten around to trying again yet. I rarely travel with them, even locally, so it's not a priority.
When I'm at home, I hate having to go in and out of drawers and boxes for tools and supplies. Nothing slows down a project like having to play storage Tetris. So mostly my airbrushes just lay about on my workbench. I've got a stand that holds 2 of them, but I think what I'd like most these days is a wall-rack of some kind. Give 'em a nice display presentation and keep 'em from being clutter while not in use, while also keeping them easy to grab when I do want to use one.