Red coris wrasses ( Coris gaimard) can get quite large ( approx 18" ) so a 40 gal
tank will hardly suffice in the future. As a whole, they are cool fish to have and get beautiful as adults but they need a sandy bottom to hide in, a varied meat diet and tend to be parasite pickers as juveniles so they can be annoying to larger fish then themselves. As they get bigger, they are known to move rocks and coral pieces so make sure your "decor is secure"
. If you are prepared to either upgrade your tank for him or give him up when he gets larger, then I say go for it.
BTW, my LFS
had a 15" one ( a.k
.a. "the submarine") in a 300? and it was tremendous. A true site to behold