Thank you Mrs music.
The plan is to have the fish clean before introducing to the 40 gallon tank. I have not made a choice as to using chemicals to treat. I think TTM and hyposalinity should be enough. I may include fresh water dips between transfers as well.
As for my fish, everyone has cleared up in my display. No visible signs of ich. The flamehawk that was showing signs is looking good now. So this is totally a preventative measure. I will also add, I was purchasing from a store that claimed their fish to be pest free. The fish I purchased have all been fat and active. The powder brown was the shocker. I firmly believe I can maintain the display as is considering it has basically all the fish I want to add, outside of a purple tang and a sailfin tang. But having lost a tank to velvet,. I opted to correct it while everyone is still young.