I've ordered a Hearthstone Shelburne (cast iron, not soapstone) with a rear heat shield and blower. I know I should get a thermometer, but am not sure what to get. Do I put one on the top center of the stove and another on the (single-wall) black stovepipe which will be routed straight up through the cathedral ceiling? If so, can you recommend an accurate model of each and give me some idea of price? Thanks!