Hey Polly, welcome to the forums!
Have you checked the TripAdvisor listings yet?
http://www.tripadvisor.com/Hotels-g317132-...Sot-Hotels.htmlThere are only 3 on there, so you don't seem to have much choice.
Did you want to fly there? There is an airport.
I don't know what the flight schedules might be like.
It looks like you might have to go back to Bangkok if you take the bus:
There are buses throughout the day from Moh Chit Bus Station in Bangkok. VIP buses are 700 baht as of June 2008. Try to get a spot at the top level of the bus (VIP) as you are not near the toilets at the bottom. They stink! There are as well, 1st class buses, and other levels. When you get the bus it goes all night so you get there very early. Remember that your ticket (VIP) gives you a free meal or drink at the stop that the bus makes in the middle of the night. When you stop take your ticket and you get one meal (pretty average) or a drink/yoghurt drink. When you arrive at Mae Sot there are Tuk Tuks and motor bikes to take you to the hotels. They are nice people and will charge depending on how many people and where you want to go.
(from Wikitravel)