Hello skuseman, I advise that you first figure out over time what type of population you want in your FOWLR
. Also, I highly suggest that you deviate from damsels because they become a nuisance, too aggressive and too territorial.
You will end up limiting your choices when you start with crustaceans first. They need security, they aren't fond of triggers, puffers, boxfish et al because crustaceans are the favorites of those types of fish.
Snails are fun to watch, especially when you have nothing but moonlight on. However, FOWLRs will always end up with at least one incident of ich. If that happens, you will try to lower your salinity, killing any crustaceans in your tank along with killing the parasites.
Algae may get out of control and that wouldn't be a pretty site as well.
Just cycle your tank well enough for at least a month, then start going through the LFS
to browse on the different species of fish. Once you figure out what you want, purchase them. Then decide whether your crustaceans and snails will be good for your tank. HTH