Whenever I get new stock my concentration has always been on assuring that the stock has fry. The fry born under your own water conditions will almost always be the most vibrant and rewarding.
To raise quality stock you will need some brine shrimp eggs which are quite costly right now. For someone who has never raised quality guppies in this manner it may be best for you to get a small amount of eggs, as you will not need a whole can to raise just a couple of strains. Please email me for more information on hatching brine shrimp eggs.