End-game warlock BG PvP Spec?

I'm thinking way way way ahead here, but I'm going to be slowly working on a 4xlock1xpriest team and I love thinking of the synergies.
Is it more beneficial for multiboxed locks to go SL/SL or srait demon for felguard?

BG or arena? They are two very distinct things.

BG's on my warlock I like to lob shadow bolts from the back or run in for the suicide hellfire after sacrificing my VW. Some pet mechanics in BG's should have changed to stop getting free rez's for them after you die if you got rid of them on purpose.

I have tried various specs on my locks.

When I got some gear the spec I found vastly superiour was 7/43/11

Reason for this:

4x felguards is VERY helpful in bg. Fire and forget on random clothie and he's basically dead (actually miss this after I started playing shamans instead)
Shadowburn - Must have for a boxer as a finnisher. With 4x of them, you should be able to make a kill each time you use it right.
Improved lifetap - When you are running with a priest, this is very helpful for downtime.

Affliction or demonology are great BG specs.

Regardless of which I always put at least 11 points in destro for shadowburn.

My personal favourite is affliction. dot up as many enemy as you can with siphon life giving health back, but it can be tiring being a beacon to rogues. I've loved battlegrounds where I've had a healer. Being healed through damage allowed me to put out the insane damage that warlocks can so running your 4 with a priest would be phenomenal. Affliction is great for mana usage with dark pact so you can dot up loads.

A 4 felgaurd build would also be quite nice. Rogues are really going to have to think about coming after you. Your priest can pop heals. You can dot up the rogue and when he pops cloak of shadows those felguards are gonna melee him mercilessly.

4 deathcoils followed by 4 shadowburns is great burst damage too :)

Were you thinking of running the priest as holy or shadow?

Yep. What Cepheus says. My lock priest team has 7/43/11 spec as well and Felguard with shadowburn (fire it with shadow word:death) provides great burst DPS that's pretty friendly for a boxer. That and the sight of 4 monstrous pets is enough to make people back up ;)

I'm a big fan of affliction. It affords you the following:
1. dots that actually hurt, and are hard to dispell (UA + contagion).. dot up and kite
2. instant fears
3. 20% extra range
4. siphon life
5. curse of exhaustion, and malediction
I played SL/SL on my main in seaosn 3 for a bit, it's nice for the survivability but he hit like a bitch, I have to re-apply dots about 3 times to kill an equally geared 70. and if it's a priest, forget it. they're dispelled almost before I even cast. I feel like a ton of demo locks is just too gimmicky. And for the ones that arent being attacked, their survivability is not being utilized yet their damage is severely gimped. Of course you could just be a one trick pony and put the felguards all on one guy at a time