I should probably point out that my build (quoted two posts above), is actually not possible. Fancy items boost 1 skill of every attribute (Strength, Mobility, Dexterity and Charisma). The build I listed above boosts Dexterity twice, and it doesn't boost Strength.
Unfortunately, the best "working" model for a "premier" dueling neck-piece would go like this:
+1 Charisma
+1 Dexterity
Appearance +13
Fine Motor Skills + 12
Toughness + 8
Reflex + 7
I say "unfortunately," because I'd rather have Dodging and Aim, to be honest. Oh, well. You can't remove the staple skill boosts (Appearance and Fine Motor Skills), but at least this build provides three very useful dueling skills in one neckpiece (something we don't really have yet).
Everyone needs to remember that neck-pieces are -- by and large -- relatively weak in stats. They are sort of like Rings or Amulets in other MMO's. They provide useful boosts, but they don't "make or break" your character. That's what Headgear, Torso-gear, Boots and other equipment are for.