On the rub, lots of folks love both, I prefer a simpler salt, pepper and aromatics rub myself. Sort of a Santa Maria type.
As for your timing, at 245F, you are probably looking at between 16 and 22 hours, which is a stupidly large range, but, there you are. I would bet on closer to 22 hours and I use the probe method to determine whether it is done or not.
I'm feeling bearish, and I'm packing a Wusthof Grand Brisket slicer from MABA
"I'm Armenian...perhaps...but then again...maybe not..."