2 new big tanks what to put in them

[gmatthewgor21]

i have 2 tanks right now that r 75g and 29g but i am in the middle of building 2 new tank in the sun room i just had built one is a 210g saltwater tank built in to the wall the other is 10ft.l 5ft.w 3ft.d saltwater what salt water fish should i put in it i want some big ones in the big tank and where can i buy cool satwater fish like that cause i live in a small town so we dont have cool fish stores all the ones here just sell little stuff