A carpenter can build the whole thing for you, including a fireplace surround. Sounds like this is what have in mind by painting the brick white. Or you could cover the brick with a tile, or some combination of the tow. Consider that if you add built-ins, they will probably extend out as far as the hearth anyway, so using a tile over the brick on the surround and then bringing it down to create the hearth might be the best way to go.