for pwps you can use fountains, the picnic blanket, the water statue (I forgot the name), the log bench and the tiki torches would also give it an islandy feel. Also, the lighthouse, totem poles, outdoor chairs, and fire pit would be perfect! You can add a couple around the entrance to the beach or something.
for landscaping, don't add too many cedars but make sure you have tons of tropical fruit c: (I can give you some if you need!) red & yellow hibiscus would be perfect in your town. at your beach lots of palm trees, coral & shells, of course! there is also beach QR's that are pretty cool!
you can also decorate your house with an island theme, using the island furniture like beach table, chair, tropical wall & floor, sandcastle, etc
as for villagers, I think octopi would be great! you should definitely add O'Hare too, I mean his look at his hat. other ideas are birds or ostriches, maybe like Blanche or Phoebe?
