there are different kinds of kribs but the care distinctions between the species are minor, as far as i know.
probably what bloozoo told you is that there are many different kinds of DWARF cichlids that are suited for different kinds of tanks.
my experience with kribs is that your tank is too small for anything more than just ONE breeding pair and a group of TOUGH tetras/danios. a single FEMALE krib would probably do ok in a community tank, but i'm no expert on keeping individual kribs.
for information on other kinds of dwarf cichlids, you should read the pinned article on "Rams, Keyholes, and Apistos" at the top of the New World Cichlids forum.