moving heat from a wood stove ?

More info is needed on the size and style of wood stove you have. Extracting heat from the firebox, not the stack may be fine if you have enough BTU waste and don't try to extract every BTU you can dropping stack temperature.
With a stove installed below the heated area, no circulator pump is required. Heated water rises, cools as it goes through radiation and drops to be reheated. Oversize lines help, and I've plumbed entire homes without circulators similar to a steam heating system pitched upwards to radiation and back down for good circulation. In your case you will need to pump it down to baseboard or radiation of your choice. You will need an expansion tank, relief valve and a way to keep system full. Normally a cold feed water line with low pressure regulator. Reasons for failure are not engineering the system properly, so you have to know how much BTU you're putting in the water, flow rate, and how much you are taking out. For example, a stainless 3/4 pipe (considered a coil) within the flames, like under a baffle plate or a stainless gizmo called "Hot Rod" is a commercially made U shape tube to heat water in firebox. http://www.yukon-eagle.com/FURNACES/THEHOTRODWATERHEATER/tabid/61/Default.aspx

The hotter the water at baseboard or radiator, the more efficient the heat moves into the air. 200 or more is best for efficiency, but you have to be careful not to create steam and open relief valve. A controlled flame in a gas or oil burner controls overheat conditions which you will experience with a stove, so the relief valve should be plumbed outside or into a drain. In the event of a power failure, a gravity system remains safe since it circulates at all times. In your case, a failed pump or electric failure which also supplies power to water pump that supplies the system may not be feasible. Antique boilers had steam driven water pumps and injectors manually operated to maintain water level without automatic safety devices but were constantly manned. There are no safeties on a wood stove to limit the heat output. (This is why you want black iron pipe or stainless sch. 40 in the firebox) Most stoves in Europe, Australia and New Zealand still use 'Water Backs" or water circulation of some sort. With the advent of oxygen barrier pex tubing (the tubing of choice) and automatic air vents (mounted at the highest point in system) it is easier than ever to design a good working system. You don't need high tech things like spiral air vents or air scoops, just a float type air vent to keep oxygen out of the system. (oxygen enters in fresh cold water when added if relief valves opens) I connect the coil with flexible stainless water heater connectors before going to pex in case it runs dry. I have a gravity system on my Kitchen Queen with 25 gallon tank on the stove built for Amish use without electric. It is an "open" system used in many Amish households without circulators or electric power.
Here's a really good book on the subject.
http://www.archive.org/stream/kitchenboilerco00unkngoog#page/n72/mode/2up