Thailand in December

I was backpacking in Thailand at the end of the 70s and would like to try it again, as I don't particularly like package tours. I'm looking for someone to explore things with, and to share meals and chats in the evenings. I'd perhaps like to go to Koh Samui or Koh Phangan again, but that's not essential. However, the beach is quite important, with surfing, snorkeling, or diving. I'm athletic, educated, and have 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 simply evolve. Without a big plan. I would, however, love to do a bike tour through Bangkok. It's supposed to be very good! I would be happy if a slim, fun female traveler would get in touch, and perhaps we could have a brief chat on Skype.