wearing vampire gear is ok if you are Dawnguard
a possible "Blade" build might include :
Vampire Armor ( Black) enchanted with extra Health and also Stamina if you can add 2 enchants.
The 2nd enchant might also be Fortify Light Armor unless you are getting Light Armor perks or have a high skill there
Vampire Boots with Muffle and/or resist fire,frost, or shock
Vampire Gauntlets(obtained from a Traveler) with Fortify 1h and/or Fortify Light Armor
Light helmet of choice- I would go with the Penitus Oculatus because it`s black and you can wear it simultaneously with a circlet which also boosts either Magicka or Archery or both
Jewelry for Magic Resist or to boost stats of choice
Blade would not drink living blood but took a serum so you will need good potions or healing spells to make up for lack of feeding if you`re gonna rp that
Skills - 1h , sneak , light armor , restoration , alchemy, archery , enchanting
restoration is great for a vampire hunter as a counter to the life drain spells
high restoration skills and dual cast perk will also reduce the cost and increase the power of your sun damage spells like Stendarr`s Aura and Vampire`s Bane
Elixir of the Healer or other Fortify Restoration potion will also boost these spells
Dagger - Blade of Woe
Sword- Ebony or a Blades with an Absorb Health
Bow- any that you like until you join Dawnguard but then a Crossbow