wobbuffet always needs 252 hp evs, so counter/coat are at their most damaging
then i'd prefer to make each defence even or there abouts, so...
a Bold wobba with 31 ivs in everything, would be
EVs: 252 HP / 92 Def / 164 SDef
forget anything you hear about hp having to be divisible by 16, for wobba it doesn't matter, you want/need max hp, so counter and mirror coat are as effectve as they can be