New Tank- Which Fish?

[Aquastrategist]

This probably won't happen for a couple months or more, but I plan on getting another tank. Currently I have a 50 stocked with 2 angels, 6 cories and a school of neons. I also have 6 juvenile rainbows. I would like to have 1 tank south american community ( cories, angels, neons) and another New Guinea Community (rainbows and peacock gobies) My new tank will probably be smaller, my question is which fish could go into a smaller tank ( New Guinea or South American) and how small could it be?

 

[Eli]

My South American tank is 120 liters, which I think is around 30 gallons. Ive got similar stocking to you, and they seem fine in my size tank but I don't think I would go much smaller because of the angelfish.