I'm no building expert, and cannot answer many of your questions, but we are currently having cabinets fabricated in order to hang a plasma TV over our wood-burning fireplace with smokestack. What we've done is rip out the existing mantel, and the built-ins that had been built around the fireplace, taking it down to the bricks that make up the fireplace and the exterior wall on either side of the fireplace. We're having some sort of floor-to-ceiling fireplace surround built, that will have a traditional mantle, and a recessed area in which the plasma will hang so that the screen becomes flush with the wall. The cabinet maker offered to build either doors that could close around the TV or a substantial picture-frame looking thing to frame in the TV, but I turned down both options. On either side of the fireplace, we're having floor-to-ceiling cabinetry and shelving built in. There will be doors on the bottom to house our receiver, subwoofer and other Tivo/satellite/etc components. The shelving above those doors will be exposed bookcases specially built to house various trinkets that we've picked up in travels, etc. We're not adding extra insulation between chimney and wall on which plasma will hang b/c I understand it's heat coming from the fireplace opening that you need to be concerned with. Hence, the need for an actual mantel to deflect some of the heat. The guy at the TV place suggested building in some sort of fan behind the TV that would extract heat. I set up a meeting b/w cabinet guy and TV sales guy at our home to map out together their mutual needs (which layed out where speaker wire and other wires needed to run, etc.). The installation was supposed to happen tomorrow, but is now delayed to next week (aren't these projects always delayed?). I'll try to post pictures after the install. When we started this project, I just interviewed a number of cabinet makers and had them bid on the project and come up with drawings/proposals. I ended up going with the least expensive, and using ideas that all of them had. There was a huge price range (with the most expensive one almost three times the least expensive). Good luck!

get a infared thermomerter and test the area above the fireplace. if its above 90* you will eventually damage the Tv.

We are trying to to the same. Currently it's a 70's brick fire place. We're thinking remove the brick add a new mantel w/ tile or something below. Above, drywall with a recessed area for an LCD (not plasma) tv. Any comments or suggestions are most welcome. We're supposed to begin this, along w/ the larger remodeling project in a few weeks.