I've been looking for one also and the only reasonable place I found was badgerbarrels.com in WI. Sounds like that's all they offer is with the cantilever and the price is around 225. I checked the website and it looks like we'll have to call to get info. Don't hold me to this info, it's just what I found on other forums. Hope this helps, let me know what you find. Check this out,
http://www.benelliusa.com/forum/show...ed-Slug-Barrel