The Nuk bottles are supposedly the best when going back and forth between the breast and bottle. As long as they are a wide nipple it is fine....Avents are wide.
I have hired a breastpump, the medela one, expensive but hopefully worth it, I will look at the babies are us reviews, I have got some avent bottles at the moment but someone told me there were bottles which imitated nipples almost exactly which were best to use, I havent found anything yet though.
Do you have a breastpump and if so did it come with bottles? I used Medela for a breastpump, and it came with bottles. I liked them a lot and have also heard that they are BPA free.
Well I just know I would not recommend using Dr. Brown bottles. Those leak a lot and they are a hassel to clean. Try using a wide neck bottle. You can go online to babies r us and read reviews and just go from there!! Hope you find the perfect bottle for your babies. Oh another thing is try buying a few different ones and try using them and if they like one just buy more of those!!