An installation we did for the Dominican Center was featured in several national trade magazines, here just a couple of the links. Engineered Systems and Reeves Journal .
Lochinvar makes a boiler model specifically for what you need
and it will probably be the most efficient boiler on the market
(look here); and don't forget about the condensing water heaters.
For more information, questions we can answer for you; or maybe a job you would like us to price out, call Bill at 509-922-1717 or email.