Chimney Cricket in Richmond, Black Moose Chimney in Antrim had good experiences with both and so have friends and family. You can do an initial inspection yourself. If you can’t climb on the roof and look down with a flashlight, I use one of my wifes old makeup mirrors and tied in on a stick, then stuck it in through the thimble. If you have a stainless liner in there you’re “most likely” fine to burn. If you have a masonry liner and see any cracks or deformation I would definitely get a professional opinion. I just finished installing a stainless liner in my stove flue last week and installed an England Stove Works 28-4000. After an hour of burn time and only 1 duct connected to the blower my first floor was at 88 degrees.