Well, seeing as how none of us have ever thought of a build like that, uhh...here's what I think I would try to do.
Keep in mind, this is not a guideline. I'm bullshitting all of this.
I will use CLVL 80 for this build, so all my stats will be revolving around what a level 80 would have with all skill and stat point quests done.
Assassins need 125% IAS to reach the 2.7 FPA with a Ward Bow.
Assassins need 45% FCR to reach the 12 FPC breakpoint.
Strength: 20
Dexterity: 20
Vitality: 20
Energy: 25
Hit Points: 50
Stamina: 95
Mana: 25
Life +2
Stamina +1
Mana +1.5
Armor:
3 Socket Mage Plate 'Enigma'
Required Strength: 55
Weight Penalty: Light
Weapon:
Widowmaker 'Lo'
Ward Bow
Required Strength: 72
Required Dexterity: 146
Base Weapon Speed: [0]
+150-200% Enhanced Damage (varies)
Ignore Target's Defense
33% Deadly Strike
+3-5 To Guided Arrow (varies)
Fires Magic Arrows [Level 11]
Helm:
Andariels Visage 'Ral'
Required Strength: 102
Reason: IAS + Leech = Awesome helm.
Belt:
Arachnid Mesh
Required Strength: 50
Reason: 20% FCR
Gloves:
Magefist
Reason: 20% FCR
Boots:
War Travelers
Required Strength: 95
Reason: Life and Damage (much needed)
Ring 1:
Bul-Katho's
Reason: Good Leech, and has +1 which helps on Guided + Tele.
Ring 2:
Rare 10% FCR / ML / LL / Resists
Reason: 10% FCR for the FCR Breakpoint, and possibly good mods.
Amulet:
Highlords Wrath
Weapon 2: Call to Arms
Shield 2: Lidless or Splendor
Inventory:
Max Damage Charms
At least 5 +1 Shadow Discipline Charms (for Damage)
Strength Required for all gear: 55
Stat points used on Strength: 35
Dexterity Required for all gear: 146
Stat points used on Dexterity: 126
I suggest at least 20 or so into Energy, because you will be teleporting quite a few times to avoid damage.
Stat points used on Energy: 20
Everything else into Vitality
Skills:
Seeing as how you won't be using a skill from your tree's to attack, and you only need 125% IAS to reach the Last BP, and Andariels gives 20%, you need 105% from Burst of Speed, with skills, of course. Unfortunately at level 20, Burst of Speed only gives 52% IAS.
Assuming you will have a total of +5 to all skills and a total of +10 to Shadow Disciplines, you will need to max the following.
Burst of Speed
Burst of Speed
increases attack and movement speed
for a period of time
Current Skill Level: 35
Attack Speed: +56 percent
Walk/Run Speed: +66 percent
Duration: 528 seconds
Mana Cost: 10
Venom
Venom
add poison damage to your weapons
Current Skill Level: 35
Poison Damage: 900-920 over 0.4 seconds
Duration: 256 seconds
Mana Cost: 12
Shadow Master
Shadow Master
summon a powerful shadow of yourself
to fight by your side
Current Skill Level: 35
Life: 2293
Attack: +1400
Resist All: +75 percent
Mana Cost: 52
Total Skill Points used: 66. The rest can be invested in a trap or something along those lines.
In conclusion, we have:
Points into Strength: 35
Points into Dexterity: 126
Points into Energy: 20
Points into Vitality: 229
20 Venom
20 Burst of Speed
20 Shadow Master
+ Pre-Reqs
Guided Arrow Cost (assuming a +5 Widowmaker): 5.7
Tactics with this build would pretty much to have Teleport on Right, Guided on left. Tele away, shoot guided, hope it hits and does damage. With this build, you can have a low Strength Requirement, saving many points for vitality.
I hope that helps some. Welcome to comments/suggestions.