If you pick up the kit lens (18-200) you will be pleasantly surprised. Being able to control iris in camera is great and the fs100 autofocus is actually a pretty decent tool depending on the application.
Philip Bloom is pretty stoked on the metabones adapter and I know others that have found it to be quality as well. Kevin Steen and Mike Clarke are both shooting canon glass on their fs100's with great success.
http://philipbloom.net/2012/01/18/newcanonmountfs100/