pewter, pastave or calico (if it's high white). Get a double morph male to compliment your females. The male pastave can give you a jigsaw, super mojo (white snake with gray head), bel (all white), mojave bee and other combos given your female. If you like white snakes, go for the pastave, if not, go with the pewter. Calicos are awesome if they are high white. Good luck!
The Calico gene does not work this way. A high white Calico can throw high and low white offspring. It works the same as a Spider's white and also a Pied's white. The level of white is not genetic.
To answer your question, I would go with an F and F line Calico.