If you are talking wild, then you can call some transshippers and wholesalers. I have never seen the ability to just request one species, though... you will get a hand selected mix and they usually will give you a few more of the ones that you like. You usually have to get 20+ and it will be well more than $1000 to land them at your local international airport. livestockusa can get you some boxes.
If you are really talking Mari, then you have seen what they have... mari grow and ship the same ones almost all the time.
There are some recent thoughts that there has only really be 8-10 different tenuis coming in and all of the different names are from the same corals.