Despite the criticism of Determination due to poor scaling, I'm personally putting in the 115 in DET simply because with my current gear and melds, its at a measly 512, while my Crit, SS, and Piety are considerably higher. I'm splitting the rest between Crit and Spell Speed, simply because I want to try and keep all my stats balanced. But as Lyrica said, Spell Speed probably won't need much attention for you, as we tend to get a lot of it.