I have a stone fireplace. I want to replace it with a wooden fireplace and mantle.
The current mantle is stone. The wall above is the same as the rest of the room. Is this type of reconstruction expensive and doable?

"with a wooden fireplace" I don't think you really meant a wooden fire place, maybe just a wooden mantle and surround. Yes it can be done and it is not a extremelt difficult job. The face of a fireplace and the mantle are usually a fascia and have not lad bearing of the fireplace. Unless you are really a skilled remodeler I'd get 3 estimates and ask the guys lots of questions. You will have a better idea of the extent of the job, alos will have estimates in plkace if you decide to not do the work yourself.