They are awesome little guys. I had some in my community tank. They love to scavenge, so you don't want sharp edged substrate. You would need a minimum of 3, but the more the merrier. Some say they eat pest snails, I did not find that to be true. They love to have caves to hide in. I would recommend 30 gallon tank minimum.
What else are you looking for?
75: blood parrots, featherfin cat, emperor tetras, turquoise rainbowfish, BN plecos, japanese trapdoor; 46: WCMM, gold inca snails, ghost, bamboo & amano shrimp, kuhli loaches, rummynose & ember tetras, endlers, platies, flame gourami, guppies; 16: pygmy, peppered, loxozonus corys, otos, assassins, RCS ... ~ Research PRIOR to purchase.... ~