Having recently lugged my gear to Peru for a trip to Machu Picchu, with most of it in a Billingham bag strapped to the handle of my rolling briefcase or rolling suitcase, as lovely as the Billingham bag is I was very frustrated by the difficulty of handling all the stuff at airports. When I returned home I checked out all of the commercial rolling cases and conclude that they wouldn't meet my needs. I was especially disappointed that none had pivot wheels, which I think are essential for anything that's rolled onto an airplane.
So I decided to build my own custom rolling case. I started with a high quality 20" leather catalog case with 2 skateboard wheels. It's long, wide, and tall enough to carry my three Nikon cameras with lenses attached, but without much wasted space. Using 1", 2", and 3" layers of dark gray foam, I totally customized the interior to hold the cameras with lenses facing down. The cameras and lenses sit in foam cradles and the bodies and lenses are completely cushioned. The top of the case holds all batteries and other supplies in custom foam slots. I removed the skateboard wheels and replaced them with pivot wheels at the four corners of the case (a task that required much cutting and modification to pivot wheel sets). The pivot wheels make it easy to roll the case sideways (or at any other angle) up narrow airplane aisles. The case fits into the overhead without any problems, and will slide under the seats of most larger aircraft. I also attached a Manfrotto heavy duty tripod strap to the case frame, which attaches the tripod very tightly to the side of the case and makes it very easy to transport the tripod.
I spent nearly a month working it but I now have completely unique case to transport my gear. It's totally suited to my needs, it's my handiwork, and it's far better than any of the commercial products, which is a reward in itself.
I'll post some photos as soon as I get a chance to shoot them.