Anyone, wanting wide shoes, will have the easiest time of it by getting the Alden catalogue. Sizes up to EEEE, many lasts and classic shoes. I think you need to order with an Alden dealer (listed by state on the website).
Getting wide sizes via boutique has options including, but not limited to, Leffot, Context, SHoemart, Citishoes, Alden DC NYC Cisco, & Molded shoe. Even they stick to E at this time.
Alden stock offerings do not include shell boots.