Gyuto is a Chef's knife, Sujihiki is a slicer, they will both work with brisket. Obviously, the sujihiki will have less drag when pulling through the meat, as the blade is thinner and shallower. You won't go wrong with either one.
I'm feeling bearish, and I'm packing a Wusthof Grand Brisket slicer from MABA
"perhaps...but then again...maybe not..."