Locks actually have pretty good CC - Seduce & Banish. Also backup CC in the form of Enslave Demon & Fear.

Tip for using seduce - make sure the lock has more agro than the succy - that way when seduce breaks, the mob will head towards the lock giving the succy time to re-seduce, and of course keep your lock at distance from the mob.

As Lost Ninja said, you probably want to keep it to 3 classes first time around to keep the complexity down. I would go with a Pally tank, 3 x Mages & a pirest. You get wipe prevention, complimentary buffs and the CC you need.

Cheers,

Stealthy