I wear a size 14 WIDE in men's boots. I am a little familiar with finding odd size boots. A couple thoughts:
1) Take a look at Danner boots. their website is down at the moment. But, when I was looking for a new pair of boots a few months ago, they seemed to have a good variety of sizes and widths available in the styles of boots that they make for the U.S. military. Seems like if they want to sell for the US GI's they need to fit a wide variety of feet. Not just the normal sizes that fit 80% of the people.
2) Call the folks at Lathrop's and Sons in Illinois. They will talk/walk you thru the process to size a boot for hard to fit feet. This is where I ended up buying my new pair of 14W Lowa Hunters.... Their "Synergy" insoles are good also. Not cheap, but good. I have two pairs in use at the moment..