Dumerils are both attractive and docile and will attain some size if you keep them properly, some female dumeril's can get up to 10' in length! I've seen a couple massive ones and they are stunning animals. Much easier to deal with than a retic IMO. Retics must be considered advanced snakes in the hobby for a number of reasons, but I don't see why Kalatoa locales couldn't be a good option for you as well. A female will get some decent size to her and weight. They are extremely intelligent and very friendly. Only downside is they still have the cage feeding aggression!
This is my pure male Kalatoa - he is special though and is an Anery (lacking red). But this gives you an idea of what Kalatoa look like in general. Be very careful buying from just anyone when it comes to super dwarf locales though. . . I know MOST of the people in the SD business. If you end up going that route, I can recc some great breeders!