I suppose if I were interested in gas fireplaces[have one in another
room] or wood stoves, I would be asking about them

as long as you are prepared to spend boatloads of bucks you will be
fine.

start by installing a proper foundation at the location of the planned
fireplace, includeing footer.



i looked into this once for a simple fireplace about 25 grand...

had better ways to spend the bucks and it would never be recovered at
home sale time