Like you are saying, if you move your filter over from the 40b you don't have to worry much about cycling or waiting months. You can move the fish right over once water in the new tank is same temperature and dechlorinated. Move filter and fish at same time. The other guy Neko's advice is well-intentioned but overly cautious (in my opinion).
So the tank is a 75 gallon with 2 senegal bichirs an angelfish and a rainbow shark? I agree I would add to the angelfish numbers, they are social cichlid and do well in groups. They come in various colors so your parents will probably enjoy them as well.
So the tank is a 75 gallon with 2 senegal bichirs an angelfish and a rainbow shark? I agree I would add to the angelfish numbers, they are social cichlid and do well in groups. They come in various colors so your parents will probably enjoy them as well.