You should really just try and get the best DpS weapon you can. If it has Stamina on it, bonus.
Strength gives you some Parry, so basically any wep you use gives a miniscule amount of tank stats.
Since your gear is going to be very tank based, the weapon slot is a great place to stock up on stats you are missing, such as:
Crit, Hit and Expertise.
Now, the only one that has any real bulk to a tank is Exp (though Unholy likes Crit a lot). But the other two can be used to help you decide between two weapons.
For intro to tanking, pick up a
Titansteel Destroyer. They're a little expensive, but you can do what I did--mine all my own titansteel. Buy/farm the other mats and tip a BS to do it for me. Works out to be slightly cheaper in the end (mat price to TSD price).
I don't know what race you are, so I'm not sure which weapons would be best (that 3 or 5 exp can be very nice, as long as you don't sacrifice a bunch of other stats for it). The TTS Destroyer will probably last you a while, either way, unless you are really lucky. It's basically better than anything you'll get in Normal mode instances.