My wife has a 20-high fresh tank. She is getting bored with it and talks about wanting a salt tank with starfish and whatever would go with them. She really likes chocolate chip stars or any of the knobby varieties (NOT serpents stars, brittle stars, etc.).

Available spare equipment to put the tank together for her:
20g high tank x2
HOB filter
heater
ProClear 75 wet/dry sump with protein skimmer (needs return pump)
standard normal output fluorescent hood

My current reef tank is leathers, softies, zoas with chromis x2, percula, purple firefish, scooter blenny, damsel (unknown variety), serpent star.

I need suggestions of what to put in the new tank with the stars and of what equipment I would need to add to the pile to make it work.