A common line would be the best way to me. One line could be used and run from one plate/spacer to the other.Let the other end tie into the water heater or some other location. But to keep the added runner lenght to a min. I would say use like a 3/8-1/2in line to plum the water from one port/plate to the other.
As for exhaust heat? humm not knowning what you have for a exhaust system,Or if some type of Heat riser would work or not. And as for a neater/cleaner looking set-up I guess that could be a 50/50 call. The water line could be run so most of it is under the intake along the balance tube.
Mark50 why not drop me a call Or a Email.
God doesn't like ugly.
