Is it a 4' or 5' 120? What species of Coris wrasse? Some get very large.
If it's a 4' tank, IMO it is not big enough for a full grown HT. Will be okay for growout for a while. Glad you are planning to upgrade.
It is very difficult to find small tusks, and I don't think their survival is great. I ordered a 1-2" tusk from blue zoo and they called and told me it died before they could ship. About 7 years ago, I bought a 2" one, and it didn't make it. They aren't easy to find, but look hard for a 3-4" tusk.