Everyone has their own personal preferences with morphs. Go to some shows and look at the morphs available there. Even if you don't buy anything it's a great way to get to know breeders and get valuable information. Since you're going to be getting 2 co-dom females to start off. Think of a goal, like what do you want to produce? People on this forum will seem like they're attacking you sometimes because there are always individuals who know absolutely nothing about ball pythons and want to breed them so it gets pretty annoying. For the third female I would recommend something like a pinstripe, or a pied if you want to get into recessives.