Your rub sounds spot on. Inject if you like. Straight to UDS is fine. Going to depend on your temps. 4 to 8 hours will be my guess. A lot of people like to foil at 160. I've done it both ways. Get a better bark without foiling. Will finish faster with the foil.
At 8lbs, I am assuming it is just a flat?
I often mix hickory and pecan.
Wannabe BBQ Illuminati