Here's what I'd personally suggest(I've got an 18 Intelligence, you don't need that many skill points)
Str: 12
Dex: 14
Con: 16 from 14
Int: 14
Wis: 16 from 14
Cha: 6 from 8
Not too big of a hit to Charisma, and you can upgrade your wisdom later, but this is gonna make you a tanky build. As a cleric, you'd make a very good tank.
I'd rather you take the higher armor class, especially since it's cheaper.
Finally, here's some feats you might consider. As well, keep this in mind: Especially based on the way you seem to have flavored your character, you might consider being an anti-hero. That means you don't get and can never use hero points, but you get a bonus feat.
[ur=http://www.d20pfsrd.com/feats/general-feats/additional-traitsl]Additional Traits[/url]; It can be helpful, depending on what traits you want or have. I'll be taking this later for a very specific reason.
Antagonize; It'll help with being a tank, though it'd be far more effective if you had a decent Charisma. Not really a good idea for first level though.
Channel Smite; Though only useful against undead, we did just go up against them, and it means that if you want to, you can keep someone alive as you beat them into the dirt. Plus, opens up a bunch of other options.
Combat Casting; Always helpful when a spellcaster is in melee.
Dodge; As a tank, higher armor class is usually helpful. This applies against bullets too!
Extra Channel; Not really for a tank, but if you want to heal a
lot, or make use of the many feats based around channeling energy, you might try it.
Fortified Armor Training; This seems like a dumb feat to take, especially considering the name sounds so much like something only a fighter would take. But at low levels, a critical hit, ESPECIALLY from a gun, will kill outright quite often. Less effective against weapons with large crit ranges(and you shouldn't be using it against those weapons), but it'll help keep you from biting the bullet.
Hero's Fortune; If you don't want to be an antihero, and really like the idea of hero points, this feat, and there's a couple others, might be good for you.
Improved Initiative; If you reach the guns first, you can stop them from firing. And, as a tank, it gives you the time needed to get between your squishies and the enemy.
Improved Shield Bash; Not because you should be bashing a lot(or ever, at first level), but because it'll remind you about feats like Shield Focus and Missile Shield, later in the game, and opens up other feats for bashing.
Sacred Summons; If you're the type of guy who'd rather let summoned stuff tank for him, or with him, this'll help.
Toughness; More hit points, especially for your relatively low hit point die in Pathfinder, are always helpful for a tank.
Warrior Priest; This seems like a pretty good feat for a tank cleric, but...I don't know. The other feats do the seperate parts of it better. Up to you.
Scribe Scroll; Often a good choice in 3.5, always a good choice now, since it doesn't cost exp. Effectively ends up multiplying your spells per day, if you have free time, or lets you have spells 'prepared' that are very situational.
Tiefling Racial Feats; Some worthy ones of note are Armor of the Pit(Better than dodge, but doesn't work against bullets), Monstruous Mask(if you want to become a goader), and Grasping Tail(like Quick Draw but better)
And almost finally, the one metamagic spell you can use, which is actually quite fitting, and would synergize nicely with your racial Darkness ability.
Tenebrous Spell. Okay, actually once I read it, it will still usually raise the spell level. Still something to keep in mind. Also nevermind again, you get Pyrotechnics, not Darkness. Bleh.
Some advice on your race. You might consider getting either get Fiendish Sprinter or Vestigial Wings, which replace the bonus to diplomacy and sense motive checks. Fiendish sprinter will help when you're running(barely), vestigial wings won't do shit until you have the fly spell. Of course, at that point, it'll be very useful. I say this because you probably won't be the party face, but the skill bonuses do go well with the Antagonize feat, if you want to be a goader.
Finally, here's a way for you to upload, save, and keep a very nice sheet that lets you get everything organized:
http://www.myth-weavers.com/forumhome.php