Do some research on here, there are many brands that people use and are very happy with. (Keystoker, Leisure Line, etc...), If you already have a boiler (gas, oil, etc..) why not just add a coil fired boiler in "parallel" with your existing boiler. Then, no mess in the living room....might a be a bit more in price, You can also get them with the hot water coils also. It would function just like your current boiler, but you just have to add coal and empty the ashes.
As for smell, if everything is functioning properly, there should not be a smell, unless you open the door for any reason. you might get a faint sulpher smell. Sometimes, the coal comes wet, and it might have a slight smell to it.