Elec/SD/Elec is likely your style stalker.
Maybe dark/ or even spines/ or another tier 9 aoe
I like the single target focused sets and find it more interesting.
Attached is a possible starting point, maybe squeeze in ball lightning.
Stalker (Elec-SD) Sneaky Boom.mxd
Minor suggestions that could open up options elsewhere.
Add somewhere
Reactive Defenses: Scaling Dam Res (3% - 13%)
Put in Fault
Force Feedback: Chance for +Rech
Add
Numina's Convalescence: 10% Recovery and 20% Regen
Energy Melee/Electric Armor/Soul Mastery is tempting.
Cramming as many fast version Energy Transfers and Assassin's Strikes into a 10 second window is of course a goal.
A sustained attack chain outside that really could hinge on how often hide can trigger. (for fET & 120.48 heal on self after 0.10s delay Only if hidden)
ET with a hide proc?
many would respond with 'yuck'
many forms of gear already are available without crafting. It is good design to have tiers and optional routes. (something like AE tickets being used for crafted IOs,. sure maybe)