Exclamation [Q] Boot Looping SPH-L900 Trying to downgrade from 4.3 to custom rom or remove KNOX

Early this morning I decided to try to get root and flash a custom rom, either CyanogenMod or Omni. I was able to flash touch recovery and wiped system files and cache. All custom firmwares failed to load. Now when the phone boots up, it goes into OTA activation, activates, does a PRL update, and reboots. Touch recovery repeats the system restore, unattended, and the loop repeats infinitely.

I am looking for a process that will help me cure the reboot loop to let me return to using the stock 4.3, but because of some bugginess I was experiencing, I would prefer a method that rids the knox bootloader and other protections so that I can gain root access and load custom firmwares.

I found a similar thread for a different model number, but I'm sure I'll need specific instructions for this model. Any help is greatly appreciated, as I'd rather not have to figure out a way to destroy the phone to get an insurance replacement. I'm also 23 days away from my upgrade date.

I am offering a $50 bounty for now, and when I upgrade, if possible to retain my phone while getting the upgrade price, you can have the note 2 that you helped fix.