95 4l60e to any year 4l80e 4x4

Have read alot of posts but maybe missing the one I really need.. I have a 95 xcsb with 4l60e. 2004 lq9 swap and psi stand alone harness. I want to be ready when the 60 goes out. I have read about repinning harness but it's for newer 4l60 trans. What 4l80e should I transplant? What transfer case? And what will be needed to make it work? Cross member? Drivelines? Psi wants me to remove harness and ecu and send both back for work. I want to have everything ready so I can do the work in the shortest time possible.