Adding a fireplace (electric fireplace heater)??

I got one in a cabinet from Wally's with the intention of ditching the cabinet and mounting it as you're suggesting. We took a couple of trips before I got around to mounting it and found we liked leaving it "portable". It fits nicely on the wall between the cabinet and slide, which was pretty much wasted space. Rolls easily and stores next to the recliner. My cabinet, which is actually deep and very useful, is still available, and we have our fireplace heater. Win/win.