End drain is an interesting twist. I can see going for the elec armor to get the nrg resist + the S/L. On top of that you'll have heals, absorb and resist from your primary. And I'm looking at end recovery as well in a couple of the powers. If you get PS, that gives you insta-end gain and end drain as a debuff.
Only thing I see there is it has same rch as Soul Drain, so I guess it's a matter of what you'll need more of... dmg or the endurance to keep spamming attacks.
Is this a soloing build? If so, you won't have the Vigilance end discount ever kicking in, so I think the elec set is a good choice. But if you team, you'll lose your dmg boost from Vig and would benefit from the SD more I'd think. Maybe a dual build is in order here... solo vs team.
If you do want to solo mostly, then I'm thinking you should look at Mu mastery over Electric. You'll get the charged armor and power sink powers that you want, but you'll get them 1-2 in the set. That way you could just skip the single target immob, unless that was something you wanted. I'm not a big fan of those powers myself (dot is pretty slow), but maybe you want it for AV fights or something. If you went Mu, and still wanted a control power, you'd have the option to snag elec shackles (st hold), which is actually a decent damage power. It does a bit more dmg per hit than elec fence, damages 2x as faster, and costs a little less endurance. Unless you plan to spam the faster immob as part of the attack chain you'd get more use from the occasional hold I think. But it looks like you're slotting for immob, so I'm guessing you want the control aspect for bosses/AVs (?).
Last thing... you're taking jump kick to qualify for Spring Attack. Seems a wasted pick as I can't imagine you using it more than once in a blue moon given all your DP options and the slow animation of JK. You'd probably get more use out of taking SJ as a second travel power to supplement SS (and you'd be ready for PvP!!!). You could one slot that as well and at least fire it up when you need some vertical movement. And bang, now you can take Spring Attack.