Siboya Sunset Resort
formerly racha resort has several bamboo bungalows for rent.
Thai-West Resort
(http://www.thai-west.com) offers a range of accommodations from economy bamboo-sided bungalows to deluxe stucco houses perched over a river that runs through the resort. there is also a place called rs home stay that operates on the northwest portion of the island but it turns out that one of the local politicians sold them some government land that the politician didn't even own, so their status is up in the air.