Supplementing

I have been EBF for almost 5 months now. pumping is going ok but it's hard. I also work as a server so my hours are very iffy sometimes. I am not financially where I want to be so I want to pick up more shifts of possibly get another job. I want to stay EBF but I don't think it's possible with how much I'm trying to work so we can live comfortably. So what I am asking is what are some ways to really build my supply or what is the BEST most NATURAL formula that I can give my babe? He's been eating baby food too. Organic kinds but his ggma gives him some gerber. Help pls.