Thailand in December

I was in Thailand as a backpacker at the end of the 70s and would like to try it again, as I don't particularly like package tours. Looking for someone with whom I can explore things and eat and chat in the evenings. I'd possibly like to go to Koh Samui or Koh Phangan again, but that's not essential. The beach is important though, with surfing or snorkeling or diving. I'm athletic, have a degree, and a good sense of humor, but not in the style of Mario Barth. I've already booked a hotel in Bangkok and everything else should just happen. Without a big plan. I would, however, like to do a bike tour through Bangkok. It's supposed to be very good! I'd be happy if a slim, funny fellow traveler would get in touch and maybe we could chat briefly on Skype.