I have a Bison Gear GFA haversack - similar to the Houndsman. It comes with removable straps on the bottom for packing a jacket or shirt. It has two water bottle size pockets outside on the ends and a good sized pocket on the face like the Houndsman. It has one 6" x 6" inside pocket with a flap - no button or snap. It has a couple of black stretchy material bands that are open on the bottom and another web loop. It also comes with a snap hook where my Mini Mag is hanging. On the back of the pack are two wide nylon web belt loops. You could use it on a belt to the tree or when slung over your shoulder, it could stabilize it on a crawl.
This one is stock and the price was the same as the Houndsman. Angelo can make the pack like you want it, if you want more or less pockets, sizes, etc. Give him a call and he can fill you in. He does return messages left if he isn't in. I really like mine and it is great for day trips.