I'd play it so that the surprise rules take effect before the attack is resolved. After all, that is kind of the point where adepts with Combat Sense is concerned; they can sense danger instinctively.
Essentially, you'd get to roll your REA+INT +6 for setting an Ambush, and depending on how covert you were I might or might not give the target a chance to perceive that you intend to hurt him (perception (visual) to notice that your hand is in fact a shock glove, or perception (hearing) to react to the sound of your shock glove powering up). Either way, you'd be at an advantage, and if the target was surprised you'd get in a solid attack, with the possibility of using Edge to Push The Limit to far exceed the 9S(e) base DV of the glove.
Additionally, I'd allow martial arts actions such as Finishing Move (-10 to your own initiative, spend one Edge), which would allow you to instantly make a follow-up attack. At 18S(e) base DV, you're likely to take your mark out in a "single" hit.
Finally, Called Shots can work wonders for this purpose. Location called shot to the Neck, for instance, has a DV limit of 10 and can Stun the target to even further reduce his initiative.
I'm personally a fan of reducing the number of "alpha strikes" to as few as possible. Most characters, NPCs and PCs both, should have a chance to avoid certain death, with the sole exception of directed sniper rifle (or heavy weapon) fire. Even Adepts are going to have a tough time dodging rounds fired from a mile away, though I would never use this against player characters myself.