heating for old building: boiler, mini splits or heat pump?

[Amy Hu]

old boiler died in 17 unit apartment building. It's been vacant for a few years. no radiators. the plumbing pipe condition unknown.

I contacted 3 HVAC contractors. 2 recommeded mini splits. 1 suggests gas heat pump.

I found some discussions on BP about mini splits with favorable experience. Does anyone have experience with it in OH?

I can't find much information on gas heat pump but would love to learn about it.