Need help with our steam heating system

Hello! I am new here. I live in a self managed 4 story co-op, with a steam heating system (boiler, risers and radiators in 8 unit building). Petri has been here a number of times to address some radiator leaking, hissing and banging. They did an okay job (it's not easy!) on portions of the work, but are at the point where they say the leaking won't stop unless we re-pipe or replace the boiler (7 years old). One owner in the building strongly disagrees and says he has someone who can look at our system, which is fine, but we generally need a few more professional eyes on the system and its issues. Can anyone recommend a couple of really good, fair, honest, professional, smart/knowledgeable Steam specialists to assess our system and provide recommendations for repair and maintenance. We would like to develop a relationship with a company who can continue to support our heating system long term. We do not want someone who will further mess up our delicate system and/or try to sell us something we don't need. Thank you so much!