Nice one on getting a 260 gallon that will be alot of fun!!
Anyway I think your stocklist could work but as the copperbanded butterfly fish can be hard to keep and you said that you didnt want this then I would pass and get a easier to keep butterfly fish such as a raccoon.
If you insist on a copperbanded butterfly then get the people at your store to show you it is feeding and that it is in very good health. Also as rainbow grouper said I would pass on the niger trigger, as they get large and with all triggers they can be upredictable. If you want to go with a trigger though I would reccomend the crosshatch trigger or the blue throat trigger as these are the most likely to be safe with the fish you want.
For more than 2 clowns I think that you could get away with 2 or 3 pairs of the clowns you want, just stay away from maroon clowns as these can get nasty with other clownfishes.
For more of a stocklist you could go with
. Some schooling fish such as chromis
. Some angelfishes - Flame angel, potters angel, emperor angel and loads more to choose from but make sure they are compatable.
. Another tang - sailfin tangs are nice as I have one now
. Maybe even a suitable moray eel if you are into that thing ( I know I am
) such as a zebra moray or if you are willing to risk a few small fishes a snowflake, chainlink or even a goldentail.
Hope this helps
