I actually only run 1 perk on specialist.  Normal perks I have SOH, Hardline, Dead Silence then for Specialist just quick draw or assassin depending on map.

I only run 1 perk because after lots of testing if you run just 1 you get your Specialist bonus earlier.  After 7 kills you unlock all the perks just like normal and this helps to get some long killstreaks going.

Not managed to get a MOAB yet (probably because of my playstyle and im not amazing) but have had a few 21 kill streaks.

Good luck

Assuming you're going the traditional specialist route, I would suggest you start with:

- (Something you like OTHER than slight of hand)

- Hardline

- (Anything you like)

Set Slight of Hand as your First Perk, this way you can take advantage of something like Blind Eye or maybe Extreme Conditioning right away. You dont NEED slight of hand until you've used some bullet and need to reload and that only happen after your first kill anyway.

That is unless you really want something else in your Tier 2 slot, but I NEVER run assasin because I don't care if people can see my on radar, I'll kill them just the same.

Sometimes I like to do Hardline as first perk, and quick draw the first one to obtain.

I got one MOAB using only specialist and the skorpion, worked quite well:

Normal perks;

PERK 1: Scavenger

PERK 2: Hardline

PERK 3: Stalker

unlock perks;

PERK 1: Blind Eye

PERK 2: Assassin

PERK 3: Quickdraw

I get the bonus all the time running this, my primary is the CM901 with a silencer; gun turns deadly with stalker on, the skorpion I think is better than the other secondaries, I love the thing.