To be honest, weezing won't be doing much damage. You should use payback or a similar dark type move for the attacking slot. Hits everything and gives an unexpected surprise to psychic types that switch in. You will be stalling out everything else. I tried fire type and poison moves, but steel resists poison, and fire and wow are resisted by fire types (which are rampant). My set is chestorest with stockpile payback and wow. I think I invested in spD and hp, since most physical attackers are stopped with Wow.
Edit: I also tried pain split, but I never found it to be more useful than just using rest for recovery.