Go back to 2007 and your story pretty much mirrors why I came to hearth.com in the first place.
I had a fisher grandma bear (8inch exhaust) running into a 7 1/4 x 7 1/4 masonry chimney. Around here, it was generally accepted (for the right or the wrong) that the top tile just always had a crack (since 90someodd percent of the crowns are done wrong) and that was considered normal (locally). I wanted to double check on here what the consensus was and how bad everyone thought my chimney was. I had lots of experience burning wood, but only local knowledge and local practices as my basis. While my chimney wasn't terrible, it might not have been up to protecting us from a chimney fire anymore so it was time to do something.
Long story short, the exterior of the chimney was just too sound, made of brick, and still good looking so I couldn't justify pulling it down to install a new chimney for the fisher (couldn't get a big enough liner down for the old girl) As much as I loved the stove I read stories on here about the gains people were seeing with these EPA units so I took the plunge. I bought my englander 30 1 year used for 450 bucks (I think, maybe 400). I was skeptical as was the wife. She grew up burning wood and her house always smelled of smoke. Ours never did with the fisher and she wouldn't let me sell that until I proved this new stove would keep the house smelling smoke free. I burned the first winter with the 30 on the masonry chimney and thought it did great. I sold my old stove for 525 or 575 to a person who hated new stoves because they wouldn't burn poorly seasoned wood
I bought a 6 inch liner and just barely got it down the chimney (should have used a 5.5 in hindsight and would if I had to do it again) and hooked up the 30. Adding the liner woke that stove up like adding a turbo! I poured insulation down around the liner because of the tight fit.
Since then, my house stays warmer on average, I burn 3 to 4 cord a winter instead of 5 to 6 cord per winter, the stove holds coals for FAR longer, the chimney is cleaner, I have a nice glass window for viewing the fire that I never thought I wanted but couldn't be w/out now, etc, etc, etc.
That said, I think you can figure out what I would recommend you start considering
pen