I will stay about 90 days next winter and need a clean and air-conditioned place. It can be small and does not need to be on the beach.
try asiarooms.com They have the cheapest internet accomodations I’ve seen so far. Best of all, you can read users’ review. There are many beach-front hotels and resorts, all inexpensive. Try The Bay Hotel (>US$35 per night). Leonardo Decaprio stayed there! The only bad news is you can’t get immediate confirmation. It’s better to book early but I’m not sure if you can book so far ahead. Good Luck!