The eternity they suffer isn't the same.
The cold one's live forever, frozen by the incessant bonds of time. They survive off of the blood of humans, killing whenever necessary, but, in special cases, they live off of animals. These cold ones, these vampires, require a large amount of self control in order to stay in the place they call home.
They have made a family of vampires among the humans.
They are dangerous.
They're only suffering comes from the loneliness of eternity and the cognizant of killing humans.
Neither of which are serious problems.
Most vampires find humans to keep them company, indulging themselves in the fresh blood with each passing of the flesh, and the ones who don't have found a partner who they have converted or who already was a cold one.
The later problem is the remnants of the human conscious that has not disappeared with their long lives. Very few of the cold ones truly care for the lives of humans, the ones who do exercise self control daily as a family in Forks, the others only few humans only as food, maintaining the human population is another part of their survival and nothing more.
The brothers of the wolves have the choice of eternity.
They can choose to remain as a wolf all their lives and protect the land that their ancestors gave them or they can choose to grow old with the family they love.
But there is a catch.
Like the cold ones they have a power that allows them to find their one true love, their soul mate. There is no guarantee that it will ever happen, they may never find the one with whom they belong, they could live for a millennium and never see that person's face or they could move on with their lives. They could give up the power of the wolves and live a normal life as a human.
But, there is always the possibility that they will find that one person that they are meant to be with and, along with the happiness that comes from finding them, they will be forever tormented. They will be forced to choose between the powers that brought them together with their love and the agony of having to watch the one they love die.
The eternity they suffer is not the same but both suffer nonetheless.
A/N: Sorry, I can't really remember if the wolves have a choice or not . . . It's been a while since I've read the books. Anyway, this was just something to get me out of my writer's block so please no flames!