I have the Marineland 20G Biowheel LED Aquarium kit. The tank is 24(w)x12(d)x16(h) and comes with a Penguin 150 Biowheel filter. I still have to do a fishless cycle so I'm not close to stocking it with fish yet but I was thinking about doing the following.

5 Gold Zebra Danios
5 Cardinal Tetras
2 Platys (1 Gold Mickey Mouse & 1 Red Wag)
4 Juan Cory Catfish
2 Tiger Snails

I know the snails don't do much of a bioload but if I have the corys do I need the snails?