Yes they love a variety. Also livebearers need a little veggie matter in their diets, so you might want to get some veggie flakes and feed it to the whole tank two or three times a week. I know your getting males, but where they come from there is a lot of decaying green stuff and algae(they won't clean your tank) for them to nibble on and they still need those nutrients. All your fish will eat and enjoy the veggie flakes.
I have had my guppies for nearly a week now, and I have noticed that they sometimes eat the algae off some of the rocks. Do guppies eat algae? They don't eat much, but I see them eating some off the rocks from time to time. I didn't think that they ate algae. Do they?