Im going to save you a lot of time.......I made that mistake. They are easily the most aggressive. I had to remove all my rocks just to get the buggers out. They will attack anything they think is a threat. When I introduced my first cleaner shrimp the damsel tore him in half before he hit the rocks. They are a pain in the butt. If your looking to have just damsels then that's fine but they will kill the weakest ones. Incredibly hard to catch.
Some damsels can be aggressive like a neon damsel. But there are some less aggressive ones like scott/azure damsels, I have these along with a couple of blue devil Fijis in my 125 with no issues at all. Remember one persons bad experience might not be another's. However, just keep doing what your doing by asking these questions.
Do LS LR water. When putting water in use a paper or plastic plate just above to sand so it wont disturb the sand. The reason I say LR next is because of water displacement. If you add it after water is in you could cause overflow. Make sure to make the saltwater before putting it in. Instead of mixing it in the tank
I would skip the sump and protein skimmer and buy dry rock and sand from an online source. Toss in a cocktail shrimp and the cycle begins. Weekly water changes and reasonable feeding/maintenance will keep you fine, providing you don't overstock.
Thanks guys! I'm planning on doing the shrimp trick, and also in relation to mixing the salt prior to putting it in the tank I do not have enough five gallon buckets so would it hurt the LR or LS if I mixed it once in the tank?