I would go with a visual Pied. With as cheap as het Pied snakes are, a possible het may be rather hard to sell, even if it is an incomplete dominate or dominant gene animal and possible het Pied (ie, a Spider possible het Pied), you would probably only be able to get the price of the incomplete dominate or dominate (Spider) for it. At least with a visual Pied, all the babies are definitely het.