Are you sure you're thinking of Patrick's? I'm pretty sure that Patrick's kit is for exhaust heat, and that Langdon's is the one that has the water heat kit.
For the record, I'm using exhaust heat for mine. Made my own plate and tube kit using a stainless plate and 3/8" brake line. Plus, the headers and tubes are wrapped with Kevlar header wrap to keep the heat in. I don't have any issue with a bog on acceleration.
