Running beams on an Escort is a bad idea, and I don't condone it, at least not for PVP. For STFs and what not, have fun, knock yourself out. But for PVP, I am highly against it. That doesn't mean I won't give you some pointers, but I'm still against it.
So if you really want to do this, I recommend the MVAM. Running beams requires less Tac slots then Cannons, so you may as well trade one in for an extra heal or magic trick; you can use PSW, Haz3, TSS3, whatever.
Ideally, your build will look like this:
Fore: 2x Beam Array, 1x Dual Beam Bank, 1x Torpedo
Aft: 3x Beam Array (OR) 2x Beam Array, 1x Torpedo
Now, I did play with this for a while, and let me tell you it can be ludicrously fun to level a target's facing shield, stun them with PSW, and then shove a tricobalt in the shield hole. It's also very difficult, and annoying, and everything in the game will kill your tricobalt so timing is critical and so is luck. Here's a suggested BOFF layout for the MVAM:
Cmdr: APB3, BO3, BO2, TT1
Ens: TT1
Lt: Target Subsystem 1, APB1
This build is sort of an Escort killer. In the MVAM's Beta Command mode, you'll have more agility then other escorts, letting you literally spiral around them and avoid their firing arc. You'll also be faster if you pop an engine battery and Evasive or Deut Tank. It's great for intercepting a fleeing, damaged escort, but be careful going up against a fresh one. To use the tactic I mentioned earlier, pick a target, activate all your attack buffs, get close, then MANUALLY fire the DBB (by clicking on it or keybinding it, whichever) and immediately after you fire it, hit your PSW to stun the target. Accelerate to get closer again since PSW will knock them back and launch your tricobalt. This needs to be done very quickly as you only have a 4 second window, and don't do this if your target already has a tactical team up, as it will simply balance out the shields and your torp will do nothing.
With practice this can be done without the PSW, simply evasive towards a target, fire BO3 to drop a shield facing and then launch the trike at the LAST possible second as you fly over/under them. I call this suicide tricobalting, as its very prone to failure and in some cases has gotten me killed if my shields were low because you are very close to the tricobalt when it detonates.
Once again, I do not condone this, this build is incredibly hard to use (effectively) and your teammates will hate you for not doing the damage an MVAM should be doing, but it can be fun to play with. It is alot of fun for PVE, I'll tell you that.