OOPS! Greg beat me to it... what he said!:oops:
You could purchase a side arm heat exchanger (around $125 on ebay) and install it in the loop to the Amtrol which itself should be a heat exchanger providing hot water from the heat of the boiler water. You can circulate the water with a circ. pump or by thermal siphon.
I am getting ready to hook up an Amtrol tank/heat exchanger to my coal boiler to provide hot water for the house in connection with the Hydronic heating loop to the baseboard heat.
If you draw a schematic of the flow of your current set up with the Amtrol, I bet we could figure a way to hook that up with the coil on the stove (using the correct placement of check valves and interaction with the exisitng boiler controls) and save the purchase of an additional heat exchanger. And yes with this setup the boiler will not fire as long as the stove is providing enough hot water to maintain temp above the boiler fire temp (although that is not going to happen often, it most likely reduce the run time since you are adding btus).
Not sure I helped you out any with my ramblings, babbling, etc., but posting a schematic of how your existing boiler/Amtrol setup works will get the experts on the forum (of which I am not one!) thinking about how to set you up.