never played a point per rush attempt league, but I'd assume that automatically favors s-jax. he's a lock for 20+ rushes this week. buffalo's run D sucks but so has best lately. I just made a play for s-jax and I don't fear the match-up much. the 20-30 yards best gets you over s-jax (assuming he gets you anything over s-jax) won't make up for the extra 2 points s-jax gets in that PPRush format. I promise you I wouldn't have made the same play for best.
At the same time though, Best leads RBs with receptions out of the backfield. He will get involved no matter how they have to do it. Plus getting .5 per catch is a safety for not getting as many rushes at only .25 per.