Pygmy Angels
Blackcap Basslet
Orangeback Basslet
Royal Gamma
Fridmani
Purple Pseudochromis
We definitly want a goby......
Purple Firefish Goby
Redspotted Sandperch
Yellow Watchman
Pink & Blue Goby
Hey, awesome. welcome to the saltyside. In a 30 gallon tank I would not go over 4-5 fish. Saltwater is more sensitive to stocking then freshwater. I see you have many freshwater tanks so you seem like you're probably a seasoned FW aquarist. Rock on!
Ok, with 2 clowns you are taking up nearly half your capacity in terms of fish...
1. Pygmy Angels - there are a few to choose from that are really colorful, but with that being said its always a gamble with a dwarf angel in a smaller tank. 30 gallons is the minimum for these guys. When you stock them with numerous other fish in a small tank its hard to know what will happen. I also have a 30 gallon tank and I considered a dwarf angel cause they are just so beautiful, but I decided not to get one (concerned about space, aggression stories from other AC members, and happiness for the fish).
Royal Gramma - This might work nicely. Depends... I've heard and seen some Royal Grammas that as they mature become quite fiesty over their "spot" amongst the rocks. If you got a small baby you might be okay. I would add the Royal Gramma last if you got one so that everyone else in the tank is comfortable and has territories set before the gramma.
Purple Fire fish - I have an Orange Fire fish and I believe their needs are basically the same. My fire fish has found a small cave which he sleeps in and darts to when spooked. This is really important for these guys. Mine is friendly and swims around alot, but they will easily be bullied by other tankmates if they are not docile species. (concerned for the firefish with dwarf angels or grammas).
Have you considered Cardinal (very docile) fish? they are lovely and would get along great with a clowns and firefish... I also think any of the sand digging gobies would get along great. I don't know much about some of the other fishes you listed. someone else will jump on that.
Basically you want to match aggression between fishes. they will naturally make their own heirarchy, but you want everyone to be as level as possible. Do not over stock or everyone will be stressed including you! lol. one more side note: the more fish you want in a small tank, the more live rock would help to filter pollutants out.
Are you going to go Reef eventually? Have you considered a clean up crew (hermits, snails, shrimp)????? THey are real important. I think the clean up crew and critters are more interesting then my fish!!!
Hope this helps.