I've been researching this for a bit actually for my Montero.
Mitsubishi actually has an option overseas for a swing out jerry can holder. Pretty sweet but it's been tough to locate and get to the US.
That said, I wonder if other brands like Toyota, Landrover, Mercedes, etc. make a similar option sold in 3rd world markets? It may be worth looking into if you have that kind of rig.
As for the old Confer carrier those only work with Blitz style cans and do not work with a Nato or Wedco can but I'm sure with enough creativity they can either be modified to work, or you can use a similar design but modified for a Nato/Wedco can.
As for making a swing out system, I've been told that generally stock sway out tire carrier systems are not going to be strong enough to handle both a spare and one or two cans so you'll either need to re-inforce them or look for an aftermarket alternative or build one from scratch.
There are companies who specialize in offering some of the parts needed to build up bumpers and may have some of the things needed but you will have to fab alot of not most of it yourself.
Alternatively, I've found with minor modifications you may be able to get an aftermarket bumper for another vehicle to fit your vehicle. In my case I was able to use a TJ rear tube bumper + a custom adapter plate. In the future I may go ahead and sell this bumper and instead buy an aftermarket TJ bumper with tire & jerry can carriers built on.:Wow1:
HTH