Our home was built in the 1950s. We would like to have an insert installed (Buck Stove 91) in our wood burning fireplace located in the family room. However, the hearth is only 8 inches and raised approximately 6-8 inches from the floor. We have been advised it should be at least 16 inches. So, we are looking for good ideas to extend the hearth as inexpensively as possible. We are also willing to consider other wood burning inserts with a capacity to heat at least 2500 sq ft or more.