I think I will. Is it something premade? Or do I have to make it?
Save yourself the amount in markup and just by a few colors of 550 Paracord and make them yourselves. Instructables.com has countless writeups with pictures and written instruction on how to weave paracord in a variety of patterns.
Not only will you save money, but there's something rewarding in making stuff like that yourself. I have had absolutely 0 experience weaving paracord; so this past weekend I gave it an attempt and the results were surprisingly good. It'll take you around an hour to make both straps if you take it slow. I ended up also making a paracord key chain since I enjoyed it so much.
Naomi, here's an instructable article that I used. This is for Bracelets; however, the concept is the same.
To get a good solid strap once you get to the end of the weaving you can knot it off and then on the tail ends of the paracord you can use a light to lightly melt the plastic on the ends and press them down. This creates a good solid connection that won't break or risk unraveling.
Read through this thread Paracord grab handles there is tons of info on making grab handles as well as door straps and more. A few post even give lengths for the door straps so you'll get a good idea, remember when pulled tight opening the doors it will stretch a little bit.
If you need any pointers or advice on making a set, i can help. if you are interested in any other paracord accessories for your jeep i am in the marketplace section on the forum (link in my signature)