I don't understand this. It's a bag.. You open up the tailgate and toss it in.Pics... Pics... Pics....
Depends on what you want to put in them but, if you are considering tools, would recommend something that doesn't get stored that far back in your jeep as you will most likely want to pull it and go to wherever the jeep is that needs the assistance. If you put the bags on the back of the rear seat then you may have to unload a bunch of stuff to get to whatever you have in those bags or lean over the rear seat to get it, then there is putting it back. In case you change your approach I have a few of these. They come in different sizes and now colors, very durable and even washable if desired. Google and shop around, can probably find them cheaper but this is a start.
https://www.rothco.com/category/rothco-military-tool-bags
This one I like. Its there but its out of the way.I have a set of the Gama roll bar bags from https://xgcargo.com/ and really like them. May add their Magellan bags, too. Definitely not a quick on/off solution, but for long term storage they work great.