Go prefab. You'll have a better product in the end because of the climate control conditions. They can scribe logs better in the factory and get a superior fit.
They completely assemble the home at the factory, disassemble it and ship it to the job site where it's reassembled. Very fast.
The builder should know what wood is best for the environment you want to build in.
Oh wait, I'm not supposed to chime in.
