Anthony, I think you aren't the only one with a large, well established tank in which fish "overcome" ich. After all, this happens out on the reefs in nature so it makes sense. However, ich can and does wipe out whole tanks - glad that it hasn't happened to you, but the people who've had ich wipe out tanks (myself included) can testify that it can happen. Most newbies don't have a large established system, a really good husbandry routine nailed down, or the experience to successfully manage a system with chronic ich.
I would say, for the OP: with all the recent fish deaths that you might want to go fallow for the 72 days and then QT all new fish you get. If your tank was stable and thriving maybe you could see how it goes, but since it's symptomatic, so to speak, it seems like a good idea to treat the situation. I don't think there is a huge rush to tear the tank apart and remove the fish that are currently healthy. You would want to plan out your TTM or hospital tank set up, how you will do water changes and keep everybody healthy outside of the DT. The fallow period for the tank is easy - it just means no fish, and the tanks just sits there - you don't have to bleach the rock or anything like that.
Once you get your tank where you want it and stable, hopefully after completing a fallow period, there are lots of colorful, small-ish fish you could try. Chalk bass or other basslets, flasher wrasses, hawkfish, dart fish, blennies...lots of stuff. Don't despair - you'll get through this and be enjoying your tank again!
