I helped someone with similar size feet. We ended up with short boots and gaiters, which are allowed in competition (check with the place/level you wish to compete at though).
Eventually he got made to measure long boots. There were no off the peg solutions.
having been in the shoe business - my recommendation would be to try the Ariat wide foot boots in the 12 and see if they work as a solution. Most of the time people have a size bigger than they need to accommodate width as we don’t tend to accommodate that well in the shoe industry unless you are really young or really old. I did my British footwear course so spent a lot of time measuring feet and have met a lot of men who were only size 8 as an example but wore size 9/10. https://www.ariat.com/gb/en/P22050_M_FOO.html