I know how to solve the lack of defense

Three words:

Chestplace of Stoicism

I use Chestguard of the Stoic Guardian now. So I have to run some heroics with my Retadin so I can get the badges. I need around 70 of them. The good thing is that BV = Threat in Wotlk. And the lost dodge is compensated by the new talent (5% dodge).