Good luck with that. Nothing has changed on the R3T for cable length. I bought a kit like that and carried it for awhile as a "just in case" scenario. Totally inadequate and I doubt if I could have made it work even in a pinch.
Frankly, IMHO, prepare to be stranded if you use those cables. Those Barnett cables are seriously heavy duty and that is what's needed to be up to the task. Plus, the Barnett's pulls so much nicer than the stock cable. Pick your cable length based on the pictures and buy the cable.
I the words of Marge Howe...If a job is once begun, never finish till it's done...be the job big or small, do it well or not at all.