Yes, 2-5 guppies sounds about right. Keep in mind that if you get both males and females, your tank will soon be overpopulated, since it's pretty much impossible to keep them from breeding. It might be best to get just one sex for that small a tank. If you want the babies, then get only one male and several females.
I wouldn't recommend cories for such a small tank. As dixaisy930 said, they want company and should ideally be in groups of 6 or more, which won't fit in there. By the way, albino cories are usually albino bronze cories, so they do get larger than panda cories.