best formula ever ever and why?

Hey moms, I've been EBF for three months and two weeks. I stay at home during the day and work 6-10 pm (hubby takes over) he feeds her pumped milk that I pump at work. I don't have a built up stash, whatever I pump tifah she'll eat it tomorrow. If she's hungrier for whatever reason she would have to wait for me to arrive. I think having an alternative at home would bring me peace of mind and will allow us to leave a little bit more stress-free. Now, I do not know anything about formulas, and they all seem great but which are the best. I don't care about price. If I'm going to supplement I want it to be the best kind. Which is the best based on your experience and why? I know nothing will ever be as good as my milk, but I can't keep up with her increasing appetite. My goal is to breastfeed until she doesn't want it anymore. Hopefully supplementing won't hurt my supply. I'm feeling kind of bad because I wish I could pump 10oz at the time like many of you do, but it just isn't happening (and yes I've tried everything). I guess fórmula it is, thanks in advance.