Achilles Tang!!! So beautiful. My LFS was telling me that this fish is INCREDIBLY temperamental. They need to be grazing on food constantly and need lots of room. Im still going to try them out when I get a bigger tank (55 gallon now). Supposedly they are jerks too so they should be the last fish.
I don't know too much about fish, only thought with the True Clowns is if you want an anemone to host them then maybe be careful what species you get. The tank raised false percs seem to host BTAs better.
I think mandarins depend on the amount of care you want to put in to the tank. There are people that keep really fat mandarins in bio cubes with no care and others that feed live food everyday. I think that 240 should be plenty big for them to live off of pods, but maybe make the "pod condos" and shake them in the DT every now and then. Mandarins are so pretty I just bought a Red scooter for my 55. He has been in a breeder box for a while, gettign him on frozen. He is eating the frozen prawn roe now, WOO HOO!
Youve got a cool list, most the fish will hang out in different areas. Maybe a goby and pistol shrimp combo or something to keep the mandarins company.