nice tank. But a green moray is pushing it big time. A 125 is not a big tank for 4 2-3 foot eels. Upgrade before you get the green (which you shouldn't anyway because they do get 8 feet, and what do you do with a 5-8 foot eel?? the aquairum most likely wont take it)
the Tesse alone should be left in the ocean.. they just get way to big.
For a 300, i would seriously just get a pair of dragons, and throw in some big fish. Hawaiian dragons are my favorite, and dont get huge. But if that is to pricey, then a zebra, snowflake, goldentail, and mexican dragon would be cool
beautiful tank, but reconsider the green for now