I'm got a 50 emp/elec and my build is quite similar, or has been, rather. I ended up ditching the invis sets for health set...invis was great for soloing, but now at 50...I laugh in the face of debt, so it doesn't matter much.
However, I would strongly suggest Zapp in place of Short Circuit. I found Short Circuit tended to get me closer to the action than my squishiness cared for. Plus, Zapp has some vicious end drain/damage and kicks some seriously booty in terms of ranged attack (I can easily pull/snipe with this baby!).
I also have Voltic Sentinal, and you will be VERY glad to have it after you fire off TB. if you fire off VS before TB, you have something at least popping damage for you while you recover. VS can be problematic because it can draw aggro when you aren't prepared for it, but I've found it's benefits far outweigh the negatives..
I never found Short Circuit to be worth my time. Also, I am a BIG fan of Tesla Cage, and might suggest you pop that in over AB. It can drain end and hold and keep you from trying to fight more than a defender's attacking abilities can allow. It's a personal preference thing at 50, but I can tell ya, with health and stamina and hasten slotted...never felt like AB gave me enough benefit to override tesla cage being absent.
And Thunderous Blast is a gift from the gods! Three slot it for end mod, and they are weak as kittens.
