Jmooney; I have a Lowepro stealth reporter D650AW, which I believe is the biggest one they do. I manage to fit 2 full size bodies, 1 smaller body, 70-200mm f/2.8, 17-40 f/4 or similar, 50mm, 105mm macro, 2 flashguns, wireless flash trigger and flash brackets, lens hoods, a healthy supply of film and memory cards, several full sets of spare batteries, time lapse cable release, lens cloths and a fair assortment of gadgetry like a torch and so on. On top of that it somehow also manages to have room for at least another lens or two, plus a big laptop and a fair few documents.
It's a great bag, but you do need to resemble a pack horse to carry that lot though
blue_iguana; Peli cases will take a real beating and come back for more. A pentax 67 should be fine in one, so long as there's enough foam around it.
Don't separate items with only one layer of foam, leave at least 2 blocks between them, more if there's room.
The only downside is that they're rather heavy to carry for any distance. I am currently borrowing an RB67 that's housed in one, and it feels pretty heavy pretty quickly.