I have a friend who has extremely large calves, and no matter what size hose I ordered for him, they were too tight in that area.

He wound up getting a pair custom made for him, and I am pretty sure (though not 100% certain) that he found them through Everything Scottish in Linville, NC. (He's also friends with Harvey Rich, who owns that shop).

Might be worth it to give Harvey a call and see what he can do.
http://www.everythingscottish.com/

Aye,
Matt