Not sure what you meant by genuinely "Thai" but the JW Marriott looks very "Thai" to me ...

The Chedi has been rebranded as The Surin & the RPYC is hardly a boutique hotel though there are some eateries within walking distance.

http://www.villaroyalephuket.com/index.html is worth a look. It's owned by the original owners of the RPYC and Boathouse.