Best formula?

My son has a very sensitive stomach and also a huge appetite and I'm unable to produce enough breast milk to keep him happy. Is there a formula that closely matches breast milk? I've done some research but would like to hear from real moms. The hospital gave me a 6 pack of ready to use enfamil newborn and he seems to like it but if there's a better option I would like to know. It'll only be maybe two bottles a day. I'm doing everything I can to increase my supply but until then I don't want him to be hungry.