I think this could be done with average mechanical skills. As long as your frame is wide enough to support two tanks, you will need a dual cylinder tank rack, a dual tank regulator/switchover assembly and the hoses and fittings. All these parts are likely on Amazon. Be sure to check all fittings for leaks when done. Or even easier would be just go to a bigger single tank.
Seasonally in the Grand Marias, MN campground
On the beautiful shores of Lake Superior
2012 Ram 2500HD CTD