Galaxy S4 Root

Hey all, I accidently updated my At&t Galaxy S4 to 4.4.2 (Well actually, it auto updated to 4.3 when I had restored stock for another reason, and that started a slippery slope) and now I can't install a custom recovery, which means no more custom roms. Normally I would comb XDA Forums for a fix, but most of the forums are vague and/or out of date.

Here's what im asking: Is there a way to install a custom recovery on (or even root?) the "NB1" baseband on a Samsung Galaxy S4 i337?

Additional Questions:

Is there an exploit like last time in the works? ("Loki Doki")

If no exploit, does the bootloader have to be unlocked as our only option?

Thank You in advance, I'm tired of getting nowhere on XDA Forums.