You're in for a lot of work. As was mentioned, you'll need to thin the hide considerably, especially if you are going break it by manually. The hump area and hide along the back are especially thick. Buffalo hides are big, bulky, heavy and difficult to work with. the one I did was an acid tan. I didn't get it thin enough, even though I thinned it quite a bit. Breaking the hide was a LOT of work but it came out nice and flexible. I hung it over a bannister but it evidently was not totally dry even though it seemed to be. A few weeks later it was extremely stiff having lost its suppleness. It's now a giant, hairy taco shell, still draped over the bannister! Or you can set it on the floor and have a hairy pup tent. :grin:
The hide from the last buffalo I shot I sent to a tannery in Texas that does them for $10/square foot. Very reasonable.
I'm sure I'm not telling you anything you don't already know. I'd done a lot of deer hides prior, but that buffalo was a lot more work.