D.,
I think that at 8 months, bumpers are unnecessary. The purpose is to prevent the baby from hitting his/her head when they are too young to control their movements. Well, at 8 months they are really past the stage of needing them. I used a bumper from birth and then removed it when my baby started crawling. I think the older they get, the more active they get, the more dangerous bumpers become.
If you think about it...there is some research to suggest that they are dangerous early on, and since the baby is not moving around, what do we need them for anyway...then they start moving around and that makes them dangerous for different reasons.
Like I said, I have used them for all four of my own babies, but removed them once they were active. I never had a problem, but there have been babies who have died because they were in the crib. I think your daughter will quickly learn where to stay in the crib so she doesn't bump her head. Binky's get lost no matter what, they just fall out under the bumper.
That's just my two cents worth. I wouldn't risk it at this point. Good luck with your decision. We moms sure agonize over every little thing, don't we? Everything is a big decision when our babies are involved! Rightfully so too.
D.