I need to upgrade the HVAC system in my house because the old AC is dead. The current system uses a Peerless gas boiler (manufactured in 1991). The hot water is then piped into the room next door where the air handler/AC coil/heating coil is located.

One contractor suggests replacing the entire system with a gas hot air furnace with an integrated AC coil. This would do away with the boiler.

Another contractor suggests replacing the boiler with another boiler, and he says that the trend is to go towards boiler systems.

What are the pros and cons of going from a boiler system to hot air system?

Two complications:

1. My wife wants "infinite" hot water because so the whole family (all 7 of us) can take baths without waiting for the water to heat up. The boiler contractor suggests linking the boiler system with the hot water supply. The hot air contractor suggests adding a tankless water heater.

2. The house used to have radiant heat in the basement, but it was disconnected before 1991. It would be nice to have radiant heat down there again, but I don't know if I want to spend the bucks on it.