I carry a lot less photo **** than that (rangefinder and one or two lenses) but in general, I stick a small padded bag or domke insert (yes some of the bags are ugly but the inserts are useful and not too expensive), inside whatever bag I'm using. The inserts don't have padding on the buttom but this is easily solved with a ubiquitous mouse pad cut up.

Backpacks seem like way too big a hassle if you actually might want to take a picture while you're carrying it, and photo bags seem mostly overbuilt and scream "I've got a bunch of expensive camera stuff in here". I had a Domke F3XB which was really nice to carry a Mamiya 6 around with plenty of room for extra lenses and stuff (although of course, I couldn't afford any but that 50mm looks so sweet). It's pretty plain sits well and you can cut off the Domke labels easily if desired. Comes in either "ballistic" nylon or canvas which wears in nicely. Also you can usually find one on eBay or a knock off for around $70. Also if you want to take a photo while carrying it, it's super easy to work from, just a flap with a clip to secure it. No velcro even to alert people you are whipping it out.