I wouldn't waste my time brining or injecting that. It's gonna taste great as is. That's a nice looking hunk of pig. I might consider injecting if I was feeling adventurous, but it's not my usual process. I prefer a nice dry rub and just lay some smoke on it, then cook till it surrenders.
Modded Brinkmann Gourmet. Basic UDS. Rescued 22.5" OTS. SJS Mini-WSM. Stubbs. B&B Oak Lump.
Cannondale 2009 F8 (for burning off all the great BBQ)