Serphent stars.
Check out KP Aquatics. I was on their site the other day and reading about many different critters and noticed they have a standard common starfish that had good reviews of living a long time. They also have several different types of starfish. They are the people that collect critters from the ocean and then sell them outright. So great prices and no middle man raising the costs up. It's a husband and wife business and highly recommended from many people. I plan on getting a few different color sponges once they start collecting them again.
Sand sifting stars also are great...
I have one of the "common sea stars" from KP Aquatics. It was in my reef for almost 9 mos. as a model citizen, no problems with fish or coral.......until I added a blasto colony, ate 1 head within the first 24 hrs., then started on another, moved to sump, still alive 5 mos. later. It's a neat star, not super colorful, but hardy.