As the title implies, I'm looking to apply the 5% crit debuff to bosses in FT / EE for my raid. What I am unsure of is the best spec to do this in currently. Is full 61 Sin the way to go, or is a hybrid of BD / Sin better for melee dps?

Any help would be much appreciated, as I haven't been able to find any info on full SL assassin raid builds on the forums