That thing is still gonna put all the weight on the tail gate. I had pretty much the same setup and it started sagging mine. I would say either make one that attaches to bumper or wait till you can buy one.
That spare tire carrier you're looking at still mounts to your cracked spare tire carrier. As far as the Smittybilt thing, that's going to put way to much stress on your tailgate. It you're looking to do all of that get a bumper mounted carrier.
__________________ DO OR DO NOT... THERE IS NO TRY.