crushed coral or sand

What would be the best substrate for a 90 gallon fish only tank? I hope to move my Niger Trigger into the tank and at some point possibly add a Lion Fish, a Puffer and/or prehaps a snowflake eel. I will, of course, also add rock and live rock.

This tank and set up are still in the very beginning stages (not even started yet), so I am looking to get advice from the start.

Thanks Bill