This is an old thread but I might be able to contribute. From my observations, hitch receiver mounted tire carriers with swing out options are built super strong, which in turn makes them quite heavy. I see them for sale all over FB and this site so I don't think you'll have an issue finding them.
Since you're driving a Subi, might I suggest you find a Subi based overlanding group that may have the exact thing you're looking for? The ones that I see on the rear of 4x4s probably checks in at 65-75lbs before the tire goes on. So, you add a 45 lb tire, a rotopax of fuel (6.5 lbs per gal x 2 gal = 13 lbs). The total now is 65+13+45=113lbs. This is on top of the cargo area full of gear and a dog! I'd think you'd want something a little lighter to start out with, otherwise, you'll need to uprate the rear springs inside the rear strut assembly.
Hope this helped!
