I have a Lowepro Omni Pro that I have used for a number of years; in fact, I getting ready to buy another one since my old one is showing it's age. I use it to carry a Field Camera, 3 LF lenses, a 35mm camera (with lens), three boxes of QuickLoads, Light Meter and 20 rolls of 35mm film. All of this on an airplane - it will fit under an airliners seat. I can either carry it as a shoulder bag, or wear it as a backpack (which is what I do when traveling). It isn't a cheap bag though. I priced it locally (Honolulu) at $330, but is probably much cheaper by mail order.