I vote for the 10 g as well. How can you get an appropriate thermogradient in only 8 in? It will NOT be the best container for the hognose, especially if get a large female. The same magazine said that you could keep a toad in a one gallon jar! Down right cruelty in my book.
BTW Martha, Andy and I will tell you that treefrogs don't belong in a 5 gallon either... 10 g per animal!