Best top up formula for colic baby?

Breastfeeding with formula top ups due to low supply, and I feel like the formula is hurting my son's belly so bad. He is so gassy, all he does is cry when he's awake until he falls back asleep. We can tell it's from the gas that is causing him to cry and I have cut dairy out of my diet. Everything else is fine, peeing and pooping fine, ect. he is just always so fussy and gassy. He is currently on similac pro total comfort. I do have a can of enfamil neuropro gentlease that I received free in the mail when I was pregnant..has anyone had success with that formula? If not, what formula do you recommend for supplementing?