You are really only asking for what to look after in a good weapon?
In that case, Conquerors need quite a few stats. These are among the best Conqueror tanking weapons in the game.
http://static.is-better-than.tv/armo...e_of_steel.jpg
http://static.is-better-than.tv/armo...hite_tiger.jpg (mainhand)
http://static.is-better-than.tv/armo...k_tortoise.jpg (offhand)
You want high base dps on the weapon. The Conq has several buffs that improves Weapon damage by a %. Highest base dps weapon in main hand when you use 1H weapons. Next thing to look for is Strength, that improves armor, damage and also stamina. Hit rating is important, if you have too low, you'll miss a lot of combos. Hate increase is useful but not a must. 36 hate rating is 1% hate, and 1% hate can hold around 3% more dps than you generate yourself (I think...). Then you got the other stats like Crit rating, crit damage which improves your damage and therefor agro. Constitution improves your survivability by adding to your health pool. Aim at 12-13k health or more for tanking.