That tank will look awesome as saltwater, you will have a very nice set up when finished! I'm setting the 265 up as salt now also, the guy hasn't talked to me since dec about getting it.
Avoid the Achilles with your life unless you're amazing and have a decade of experience in SW. I've only seen one alive in a tank.
Panther groupers get to 3' in the wild. Don't get one. Clown trigger-- absolutely yes-- as long as it's the last fish in your tank, you feed 3x/day, and you get it young. Humas are the most peaceful triggers, we're getting rid of ours because it just eats too much. It's ridiculous how much it eats.
Get a zebra moray-- one of the best saltwater fish period. Not too big, not aggressive, fun to handfeed.
