Supplementing moms

Supplementing moms how did you go about choosing which formula ? My son was born at 36 weeks and left the nicu on human milk fortifier and was also given neosure for when that runs out but my pediatrician said to stop the fortifier and just do breast milk since he was happy with his weight gain after only a month. He’s 8 weeks now. I’m not pumping enough for what he’s taking in but I’m also not pumping every 3 hours anymore because it’s taking a toll on my mental health. I don’t think I want to use the neosure since his pediatrician is happy with weight gain and he is colicky and has reflux so from the reviews it seems people say neosure makes it worse. How did you choose your formula?