Magma Riot DJ XXL pack is one of the best bags for transporting this type and size of gear. It comes highly recommend by someone who has used this bag for over two years and completed over 50 trips with my gear for many purposes.
This is just an inactive snapshot of the bag and some images on the site…
Click the link for further info:
http://www.magma-bags.com/produkte/riot-dj-backpack-xxl/riot-dj-backpack-xxl-2-e.php3
It often looks big in pictures but in person, it is the right size for carry-on/overhead cabin space and has modular pieces in the inside so that you can fit and secure your gear in a great mobile pack. You can carry a 19" laptop in a separate pocket and a bunch of cables, headphones, etc.
Plus, those compact foldable carts you can get at the airport will work perfectly for convert it into a trolley bag. It also has straps to secure the bag to the cart. I remember buying this at the 2013 BPM Show and the guys at he booth mentioned that the bag was made and tested with this use in mind but they didn’t make a cart for it since there was countless options available.
The bag has those plastic/waterproof type zippers which can be locked. There’s a waist and adjustable staps to make it a book bag and/or you can carry it horizontally, like a case. Many options.
Kinda expensive but once you see the inside and the modular pieces, you’ll know it’s an awesome bag.
No offense to Mono bags but the material construction of this bag is superior. The best way to describe it is that all of the seems and angles are made for travel and the all-over black appearance is awesome because nosey people don’t pick-up what you have until you open it up…oh yeah, it opens in two halves like a clam shell and in the compartment you fasten your gear, there’s a flap and a belt to hold stuff in place. I place one modular piece in between my hardware units and all is good.