I also vote wood stove
Make sure to keep out the right angles, and use the proper piping...
also its imparative to brace your exterior pipe
annnnnd get 2 of those pipe thermostats.... say one about 3' from top of stove, and one near the stove... also, as an added safety feature, esp if you have limited to no experience working a stove, put in an in pipe damper... if the stove ever gets away from you (like when its super windy, you can shut it down with out water... water + hot stove = possible steam burns, busted stove, or worse...
now for your stove, if you go second hand bring a flash light when you go look at it, be prepared to get dirty, and a 2 inch paint brush
your looking for cracks in the stove. any cracks, run.
the bigger the stove the better. and stay away from those fireplace models,
an excellent resource: hearth.com
oh and a stove with a blower, is absolutely worth it.