Shaggies, by Rancho Safari came large, at least when I bought mine. Large as in, very voluminous so you can wear a fanny pack etc.
Cabelas used to have them, I guess now 3Rivers does, or order direct from RS on-line.
Something to consider.. RS makes a Bowhunter deluxe version and a longcoat version. My OWN experience is that the Bowhunter version is fuller (more stuff sewn to it) and may be more cumbersome, while the longcoat is less full and trims up right fine. It is also a bit less expensive. Mine was called the ultralight back in the day, I think it is just the LCBU version (no jute or burlap) now. If / when I buy another, it will be the same as what I have.
Remember to wear it for practice and trim whatever needs to be gone. Don't get excited, it helps and it doesn't hurt the coat's effectiveness.
CHuckC