We are likely headed to Thailand in November and will fly in and out of Bangkok and also visit my brother in Chaing Mai. Wanted to close with 5-6 night stay at a 5 star resort (but not over-the-top in terms of price). From the maps, a few of the properties on Koh Samui looked ideal - nice properties, great rooms, and close enough to a town so we won't get the "stranded on property" so we can head into town for meals and knocking around. But the rains will keep us away. so please suggest resorts in Phuket or the Gulf Coast.

Any suggestions welcome.

Samui is on the "Gulf Coast"—or "at least an island off the Gulf Coast.
November is not only the wettest month on Samui but also on the southern Gulf Coast.
So you need to look at the Andaman coast—typically Phuket, but also to the north, Khao Lak, and to the south, Krabi. On the Andaman side you could even engage in a bit of island hopping.
Phuket is the most expensive part of Thailand, but hotels are still good value by international standards.

I suggest you do a search on Google Maps - pich a location and thenclick the "hotels nearby" option - you get a comparison of booking sites and get a good idea of location.