The only thing I see that may cause a problem is with the yellow tang. If you get a
WC tang and they have problems then you will have to get rid of one.
IMO you will be fine with that size tank. The
WC tang is not aggressive. I have one and love it! It will take a few days, then it will be eating out of your hand literally.
Check my gallery for a pic of it.
PS. They are very hardy. Mine was shipped form DFS and has went through
QT and 2
QT and ich treatments just fine.