I have a 12 year old chimney, clay liner that appears to be in decent shape still. I have a cat stove on the living floor level attached to the chimney...if I take the stove pipe off from the stove and look in directly across the liner has some small cracks forming, probably from years of heat. Nothing missing, just a few cracks...you could probably detect them with your thumb nail if you reached way in and felt for them. Anyway, from the stove inlet to the peak is 17 feet...what's a rough cost to expect, and what would I ask for? From what I've read, insulated flex stainless pipe if what I need right? Who do I call....as in how do you find a reputable installer? Just call some chimney sweeps in the area?..or stove shops?