Hi from Sweden
I also have a 2 door, problems with cargo space.
Not the best help from me
I put stuff on the front passenger floor area.
Maybe not the best for You and heavy stuff, but be good to mention this.
I have the bestop sadle bags. I have mine much lower.
And use raingler net (RPB roof net) at the roof for clothes, sleeping bags etc. Can have on in the front and one in the back. From Jeep Wrangler 4Door
Other straps http://www.safaristraps.com/index.php?route=common/home