R.V.
Hi Courtney,
The type of nipple you want to use really depends on your own letdown reflex. I had the same issue. It's a little hard to tell, but when I pumped I kind of watched how fast the milk was coming out. Then I squeezed water through the nipple to how much came out at once, and just compared them. Also, I went by my son...he was obviously getting frustrated with the really slow nipple. We ended up using the Avent size 2 nipples, and the Playtex fast flow ones. But it depends, I've heard of women whose letdown is so fast that their babies need the fastest flow nipples possible.
You do have to work to keep the milk supply up, but even if it's easier to get milk out a bottle, your baby might still prefer to nurse. I know mine does...seems to be the best part of his day, LOL! It's not just about the food, he nurses for comfort and snuggling too. Good luck!