Breastfeeding mamas - bottle nipple flow

breastfeeding moms - have any of you changed the flow of the nipple on a bottle? My son gets a bottle 2 days a week while I'm at work and we love the ComoTomo bottles. I've thought about getting the next size bottle since he is eating 4.5oz each time and the little bottles only hold 5 but I know the nipple on the larger bottle is the next stage with a faster flow. I know the flow from the breast is totally different even though he seems to be quicker at extracting milk.