Mogurnda species (purple spots) are easy to breed, just establish a male/female pair and keep them in a tank alone, within a couple of weeks they will have bred and there will be eggs in the tank.
Hypseleotris compressa can be tricky to breed. You will need a flat surface like wood or a stone for the eggs to be laid on. The male guards the eggs until the larva hatch. Feeding the fry is very hard. No reports have occured of a fully successful breeding.
I would concentrate on Purple spots.
i have a couple of bathtubs spare. Purple spots and empires are found locally in my area so temps are fine. Not sure on size but its plenty big enough for a few just need to know will they fight?
adults i feed on a commercial diet aswell as the addition of live shrimp and and fish. If i can find a local population will get a few from there otherwise will buy some in the coming weeks.