Alternative to Barbour?

I'm looking for something similar to a Barbour waxed coat that I can wear on rainy days and that let's me comfortably shoulder a shotgun. I tried on a bunch of Barbour coats but nothing they have will fit me for my purposes (i.e., while I could walk around in it fine, there's not enough room in the shoulders to shoulder a shotgun, even with alterations). The salespeople uniformly agreed that Barbour just don't make coats that will fit me based upon my build. I'm fairly tall, have broad shoulders, a thick upper back and a small waist.

Any thoughts on alternatives? It's not a big deal if I can't find one, but if someone has a good idea then I'd be interested in hearing it.

Alternative to Barbour?