Fireplace question - attaching framing/sheetrock

We've got a house that was built in 1983, looks like a metal insert in the fireplace, and it has gas logs in there currently. There are three tubes at the top of the insert that the heat goes past which supply heat out the front of the vents above the fireplace. Looking up in the opening, I can see the inside of the chimney, so there is not a metal insert/tube running all the way up. The Chimney is bricked all the way up.

We are getting ready to remodel the living room, removing all the paneling and putting up fresh sheet rock. The plan is to build a built in on each side of the fireplace, and I would like to sheetrock over the top of the fireplace from where the mantel is currently and up. This will allow me to run all my wires, and have some stud work to mount a tv to. We'll resurface the face of the fireplace probably with some new brick or other type of thin stone made for refacing old looking brick work. My question is, am I doing anything dangerous or that I shouldn't be doing by covering up the brick at the top on this masonry type of firepace? I know I have clearances from the opening, but what about putting studs right up against the brick up top? I know the ceiling touches against the chimney, so can't see how this would be different. Below is a picture of the fireplace, and a rough sketch of what I'm thinking.

Should be fine as drywall typically counts as a non-combustible.

Not sure I would do it from a pure aesthetic standpoint but that is me.

There is regular drywall and fire-code drywall; http://www.usgdesignstudio.com/fire-resistant-assembly.asp?id=161

Check with local AHJ for guidance rather than the internet...http://www.rumford.com/drywall.html

You may be fine as it is above the combustible (code-clearance) mantle, check to be sure.... and approved for your H.O. Insurance carrier if ever a claim.

Gary