New Boiler Recommendations and Questions

Hi, We are shopping for a new gas boiler. We live in a 3 story brownstone and currently have a 175BTU boiler that is probably 50 years old. We’ve had several people out who have quoted different products and after reading online we’re confused. Williamson 175 is one option. The AFUE rating is 82.2% New Yorker is the second option. Basically the same energy ratings. Do we need to get a higher efficiency boiler? Online I’ve read 90%-95% are considered high ratings. Both people who’ve come out to our house have told us that it’s impossible to go that high because of the way our system is set up, it will get the water too hot. Basically I want to know opinions on those two boilers and what I should be looking for. Thanks so much for any advice or guidance.