Hey,
Go very slowly! I know you want to get things rolling along and looking cool, but go slow and save your self a lot of heart ache, and cash. Once your water has checked out ok, get a good clean-up crew and maybe a pair of cleaner or peppermint shrimp and see if they survive. I'd personally wait for a month after adding the clean-up crew. Then I'd try something real hardy like mushrooms or maybe a leather coral. (Just one! And then wait again.)
As far as additives, calcium and iodine are all I use. You may need a ph buffer of some kind. I try and keep my tank as simple as possible. You'll get answers from people who must use every available chemical on the market and swear by each one. It's a personal choice you have to make.
A non-chemical additive I like for my corals is DT's phytoplankton. I use that at about 1/2 the recommended dosage.
HTH, Dan'l