Personally I would find male morphs that are super forms, double or triple genes, like a BEL, Lesser bee or Queen bee, a killer queen bee wouldn't be bad to have because everything you get would contain the pastel gene. As for pieds it really depends on what you want to produce. It might be an idea to buy a male pied and several females that are het for pied. You could get some pastel or spider females het for pied and have a 25% chance of producing spied or pastel pieds.