Bottle nipple question

I will be pumping, and need bottles. My friend gave me some new bottles she didn't use with her daughter that have 3 month + size nipples. 
​With my first son, I remember the newborn flow nipples being too slow for him and he got frustrated. 
​Would you go with the newborn size anyway? Or go straight to the slow flow? I'm not sure what to do bc I don't want to waste money, but I want to make sure baby 2 has what he needs. Thanks!