E/N (later maybe E/Mo) weapon question

Which combination is better at the end? Wand + artifact (foci?) or two-handed staff? What staff or wand + artifact you are using with same professions?

Is this staff possible in game? And what requirements base staff has?

Insightful Staff of Fire Magic

11-22 dmg (what damage type is best, shadow? because ignore armor?)
+15 energy (+10 base, +5 from staff head upgrade)
+1 fire magic (from staff wrapping upgrade)
Improves casting speed using Fire Magic skills (Chance: 20%)

If yes then how much it's worth?

Staffs have the POTENTIAL to be better than a wand/foci, the trick is finding one that's good enough. Max damage wands and max energy foci are plentiful, just the right staff is not.