I plan to breast feed, but also use bottles with breast milk in them. How many bottles should I register for? Varying sizes?
What do you store your breast milk in?
I'd register for the single bottles in a couple of different brands and the packs of what you hope to use.
Playtex drop ins have a breast milk storage thing so you can store in the drop ins that you put in the bottle.
My advice is to skip the small (4- to 5-oz) bottles and just get the larger ones. Especially since you don't plan to exclusively bottle feed. The small bottles are only useful for a couple months and then baby starts taking 5+ ounces at a time (DD drank 5+ oz in one feeding at 2.5 months old). You can feed them from a large bottle from day 1.
I agree with others who said to get a variety, since it's one of those things where every baby is different. DD preferred Tommee Tippee Close to Nature bottles, as well as Dr. Brown's. We probably had 5 or 6 bottles in rotation every day, but I bottle-fed full time.