Every weapon has the same weapon damage range and speed for both instanced and non-instanced pvp. The only different will be the stats and things like shadowfang's proc damage. The list of weapons and their ability damage can be found
here. If you really want to figure out the best wpvp weapons, make a copy of that spreadsheet, add a column for agility, and tweak the standard stats (verse, AP) to match your char sheet in wpvp gear (minus a mainhand weapon). Then tweak the formula to take AP+agility instead of just AP.
Shadowfang, like always, will probably be extremely good for damage. With 5 agility, the reasonably slow speed, and the proc - it will be hard to beat. The heirloom sword/mace will be very close with better weapon damage and general stats instead of max agi. The titanforged invasion axe (34) will also be pretty good, possibly BiS. Its stronger weapon damage than shadowfang, and has better stats than the heirloom weapon. The offhand will be a stat stick and white damage, so a TF invasion weapon or shadowfang will likely be ideal.
Common legion blade is interesting. If the PTR changes go through (likely tomorrow?), then its not worth using. Otherwise its so strong that it might be worth using mainhand for the ability damage. If it maintains the 5.0 attack speed, then elemental force may not actually be the best enchant though. The way enchants work is they are normalized over a weapon's attack speed - so a fast weapon might proc every other hit (50% proc) and a slow weapon might have an 80% chance to proc. CLB is sooooo slow that you would have well over 100% chance to proc elemental force, meaning a lot of damage is wasted (having 150% chance to proc is the same as having 100%). So something that procs less often might have a more efficient proc rate - perhaps landslide would be ideal.
For daggers, the TF and WF daggers are going to be the best options. Talon of Vultros is slower for high mainhand damage, but without the scaling we used to have, the stats on it are pretty low. If you don't have the better invasion daggers, then Talon and/or the 1.8 attack speed heirloom dagger are solid options. With wpvp, the offhand weapon actually factors into things like mutilate, so I wouldn't use anything other than an invasion dagger or the 1.8 speed heirloom dagger. Poison procs aren't normalized either, so a fast offhand is good to keep reapplying poisons.
