Why a twin Coil Nick? How are you going to set this Up?
I'm guessing you are going to use one side for the Bio and one side for your shower?
It would seem to me double heating the Bio would be overkill and may possibly not be a good thing for the Bio to be too hot before going to the IP on your car. I know some of them are better with cooler fuel rather than hot, don't recall which ones though.