"I think turning a non TF into a TF could be the hardest thing to do in TFing."

I think that Derek probably is talking about a timber frame as opposed to a trimber frame. It is very hard to produce a timber frame that does not act as the frame. In short it is not the structure. If I were you I would go with cabin as well. You will learn more than just placing timbers with big screws. And it is more fun. I have done both. Good luck with your project, and ask questions there are always informative answers around here, that are not necessarily the same. There is more than one way to skin a cat.

Mo