Hi everyone, I'm considering buying a Hearthstone Equinox and will need to replace my 6" metal chimney. I would like install a masonry chimney on the outside of the house this time and I am interested in opinions between an 8"X8" V's 8"X12". Chimney Height will be 30 feet total. 20 feet above thimble. The Equinox has an 8" flue. Also if anyone has a Hearthstone Equinox I'd like to hear from you, not too much for reviews on this model. Thanks.