Cinder blocks are not a good Idea for a wood stove, they can not handle the heat
you need to either get a freestanding wood stove or make one out of 55 gallon steel drums
http://www.northerntool.com/webapp/w...70_20894_20894
link for kit
you need to get tubing designed to be stove pipe as the exhaust will be hotter than air duct will handle for long, galvanized duct should not be used, the zinc will melt off