CichlidFish.com - Fish That Think.

I'm a long time fresh water cichlid fan setting up my first salt tank. My question is this, Is there a waiting period for each step of the salt water process. I mean do I have to wait for awhile with just the water before adding the sand, and then more time before adding the rock, or can I add sand and rock together. How long should the water be mixed and filtering before adding them? I'm doing marine not reef, 55 gallon. I want to have a lionfish, porcupine puffer,a trigger and maybe a flame angel. Any problems with that combination. oh yeah maybe a snowflake eel. But I think that might not work. Any advice would help.