Have you thought about something like these. They weight of the tire rides on the bumper but attaches to the tailgate for easy opening.
https://www.jcroffroad.com/product/SWBB/SWBSC2.html
http://store.arbusa.com/ARB-Rear-Tire-Carrier-For-Jeep-Wrangler-JK-TJ-YJ-5750300-P22693.aspx#
https://www.jcroffroad.com/product/SWBB/SWBSC2.html
http://store.arbusa.com/ARB-Rear-Tire-Carrier-For-Jeep-Wrangler-JK-TJ-YJ-5750300-P22693.aspx#