I have had a variety of plants. I have had mangroves, but would suggest a mud substrate with those. I would say uour best bet is cheato or
Ulva sp.
My tang and coral beauty love the ulva aka sea lettuce.
Aquarium Fish: Tropical Freshwater Fish and Saltwater Fish for Home Aquariums has both and
www.sealifeflorida.com has the ulva when in season. sealifes Ulva comes flourishing wiht life like amphipods and whatnot.