A couple of the large Asian groceries north of Seattle, 99Ranch and HMart, have 'long cut feet'. The prepackaged ones tend to be cut crosswise through the bone in multiple places (leaving some skin to connect the pieces). But you may be able to ask a butcher for an uncut piece (though there might be a language barrier). I believe 99 has a store in the south suburbs as well.
Mexican butchers (carnicerias) might be worth a try. There seem to be good pockets of Asian (Korean) and Mexican shopping on the southwest side of Tacoma.