I'm making a lock as well and I'm working on a set.
im SUPER familiar with lock theorycraft so I'll do my best but you have the right idea.
Off the top of my head, I would go Stam (To Reasonable Amount) > Int/SP > Haste > Versatility > Crit => Stamina. IMO this should hold true for demo as well. I'll try to make some theoretical stat weights in a bit.
Destro would be different (Probably more like Stam (To Reasonable Amount) > Int/SP > Versatility >= Crit > Stamina > Haste
So I thought about it some more and I would def do: Stam (to a reasonably health total, i.e. 6.5-7k HP) > SP/Int >= Haste > Versatility > Stamina > Crit
Cantstawp @ Korgath - Community - World of Warcraft - this is what I'm running, although I play it mostly as Destro. I only swap Aff when the other team has a good healer I need to shut down. I'm going to make a MS UA set w/ max int at some point I suppose.