tkdwoody - In my tank I have astrea snails, cerith snails, trochus snails, peppermint shrimp, cleaner shrimp, harlequin shrimp, brittle stars, scarlet hermit crabs, and nassarius snails. I like inverts and they all do pretty well. You can add any of these and many others. I would skip the harlequin shrimp though, they only eat starfish.
As for fish, I like wrasses. A 6 line is not a bad choice but for some reason I think he should be a late addition to the tank, but I can't remember why.....
Many people have Chromis by themselves but they prefer to be in groups. Even though they are fine for smaller tanks, I didn't want to fill my tank with just a school of Chromis so I avoided them.
Gobie74 - Yes, thanks for the reminder, that is what I was getting at in my first post.
DO check for copper. You are using a hex tank as a sump and my guess is that this tank was used. If the fish in it were ever treated for ick with a copper based medication (most are) it will never be good for saltwater.