My usual kit is a Chamonix 45N-1, three lenses, 10-12 holders, and accessories. I use a LowePro Mini-Trekker pack, and it seems just about perfect. I also have a Pelican 1510 rolling case with padded dividers, that offers more protection and is legal carry-on size. I've also used a Domke F4AF bag and it worked fine. You don't need to overdo it with the Chamonix--it's small and light, so why get a heavy bag?