Our son's been breastfeeding pretty well for over two weeks now. My wife and I are thinking of introducing the bottle in another week or so, mainly so that I can help out with the feedings. It will be pumped breastmilk, no formula. He'll still be mainly breastfeeding, just the occasional feeding with a bottle. The question I have is which kind/brand of bottle to use? Is one preferable over another if you're going to continue breastfeeding?