Are coppper coils availble in a forced air unit

I was delighted when I moved into my house to see a coal furnace in the basement..... however.... it is an extremely old model with a firebox about the size of a shoe-box. I'm looking at the keystokers now, and they seem great, but since I have forced air heat, I'm assuming getting a boiler is out of the question unless I want to install radiators and run pipe throughout the house..., correct? If a boiler's not a possible, can I obtain the coppper coil in a forced air unit? Sorry for the dumbo question, but the dealer in my area is not very knowledgable...

Thanks!

I have an AHS mulit fuel boiler with forced air. It is just about as simple as it comes. Especially if your forced air unit is already installed. You simply put a Water to air exchanger inside you plenum (sp?) right above the blower of your forced air unit. ANY heating company should be able to easily do this for you...
One thing about the heat exchangers however is this. If you buy and install say a 80,000 BTU heat exchanger. That is ALL the heat you are gonna get. even if you have a 200,000 BTU boiler your output will only be 80,000. Get the biggest heat exchanger your duct work can handle.