...ended up going with the Viessmann Vitodens 200 Boiler. When it took a full 4 days to install, with a lot of new piping and wiring, I felt better about the high price...Ha!
I ultimately chose to go with this unit as the heat exchanger and other internals are stainless steel, (as opposed to aluminum), so theoretically it should be less susceptible to corrosion and leaking. And it is amazingly quiet...you cannot hear this thing go on!