I know this may sound stupid, but you may want to wait until after you have the baby to buy the pump. I rented a hospital grade pump from a lactation consultant. Everything is new to you, the tubes, cups and stuff like that, but you hook them up to the actual pump that is the hospital grade. That way, you can find out if breast feeding is right for you and your baby before you invest hundreds of dollars into a pump that you may not like or use.
My hospital had a lactation consultant there and also a list of consultants that you could call. It was really helpful and I am soooo glad I did that before I bought my own. My son wouldn't nurse, so I was continually pumping and my body couldnt keep up and stopped producing milk. I did everything the doctor and the consultant said to do and it just didn't work. So, I am really glad I rented.
I hope it all works out good for you, but I really did find the consultant a big help.