We live in the Northeast, and want up to 200 BTU/hr output high efficiency ( 90%+) gas fired boiler. Understand Rheem, Buderus and Peerless are good. What are the key considerations/ issues? We will have to have power venting (eg no chimney -- boiler located in a basement, without chimney access -- vents out the side of the house. We have make up air installed now.