Contractors for chimney removal and replacement?

We need to remove a failing 100-year-old chimney and fireplace, and are hoping to replace it with a gas fireplace. If anyone has done this work in the past five years or so, I would love to hear who you used and whether you were happy with the outcome. (We will be doing some other renovations, including a foundation replacement, at the same time, so either a GC or a chimney/foundation-specific firm would work.) If you had to remove a fireplace, what did you replace it with (if anything)? Thanks!