Yes, you can swap in the 8.4 screen. There are 2 different versions for the 8.4, one with Nav and one without. You will also need to make some changes with Alpha OBD or J-scan and have to purchase a new center bezel to mount the new screen to. If you want the nav version of the 8.4 you will keep your existing radio module, if you opt for the non nav unit the module is integrated into the screen already and you could sell your module and screen together, which will sell fast! Like you mentioned you could also find someone and do a complete swap.