Hmm, from those two i would say eth BoTD because it would be 3 frame faster than the maul (9fpa feral vs 6fpa one), but just so you know, there are other possibilities than runeword weapons... as a matter of fact wolfbarb just as most wereforms get the most out of non runeword weapons, for example if you had a cruel colossus blade of quickness with 3 sockets from .09 you could go and add 3 ed/ias jewels, making that colossus blade a 4fpa weapon if you use it with a shield (1H mode)..
The speed needed for 4fpa on 1h weapons is more or less 80%ias for base speed 0 weapons(Berzerker Axe, Balrog Blade)
75% ias with a base speed -5 weapon (Highland Blade)
70%ias with base speed -10 weapons (War Spike, ScourgeÂ´s, Champion Swords)
Try and do the math, last time i saw it the dmg was too low to even make the opponent care about your speed... Gris caddy is better used by characters that can carry high elemental dmg... not the case of a wolfbarb...