Spare tire carrier

If I understand you, you want to find a swing out spare tire carrier to mount onto your stock bumper?

That stock bumper is made of thin steel. And it isn't some type of 'high strength' steel either. So adding just the carrier would be at the high end of what the stock bumper can do with out massive amounts of bracing and support behind it. That would end up with little weight savings. Which is what i assume you would be going for since the stock bumper is ugly and mostly ineffective. Find a good aftermarket bumper that is built correctly to hold that extra weight that looks and performs much better than stock.
--just one old guy's opinion--