Hognose snakes stay small - with an adult size ranging from 18-36 inches for most of the US forms. Southerns are the smallest, Westerns are bigger, and Easterns are the largest of the group.
Westerns average right around 2 ft, and are probably the easiest to maintain.
Easterns have a more specialized diet, toads being a preferred prey item, but they can usually be switched to mammalian prey. (When I kept them, I used rat pups as the primary diet & never had a problem...I don't know if furred mice would present a problem
I have no experience with Southerns, but I have heard they are a bit more difficult to keep.