Typically for single target, AS or EM will be best. You'll want to align EM's w/ your PET's. If you want to get away from the whole pet thing, UF sims very will too. I play AS/UF all day every day, and I generally like it. UE becomes top priority, and you'll want to hard cast LB @ 3 stacks more often. You can still see big burst numbers depending on how you open up, as well. I typically will see anywhere from 60k-90k burst depending if lust is used/trinkets proc in a timely fashion. The trick to this is your opener, when running UF I typtically pop FET @ 3s to pull, then LM/pot when pull happens, I ascendance > SS > UF > double lightning bolt (one being AS, one from MWx4-5), I'll FS, LL and usually have another LB @ 3-4MW stacks ready, then use SS again, and continue from there, weaving in frost shock when possible. You want to try and get as many LB's off as possible within that first UF because they will hit like mac trucks, and if your scales of doom procs, that multistrike + the 5% from UF = insane.
Here's a link to my armory -
http://us.battle.net/wow/en/characte...asomnia/simple (As of now, it's my pvp set up, I hope it changes back to pve, by the time you see this.)