If you want to keep the console exploitable (with the JTAG/SMC hack), you'll need to perform the hack before doing any updates. It's been a while since I've hacked a console, but I believe you can use the Reset Glitch Hack (RGH) to hack a console that has been updated past update 7xxx. (Don't quote me on that and do your due diligence.) Both are pretty different processes, so you'll need to decide which method you want to use before going forward.
