If you want to formula feed, that's perfectly fine, but I just wanted to tell you that it's absolutely normal for your baby to get almost no milk -- just tiny bit of colostrum, which is very rich -- for several days. Their stomachs are only the size of a marble, though, so they don't need much! Your milk doesn't come usually for 2-5 days, and it's absolutely normal for a baby to lose up to 10% of its birthweight before they start gaining it back. Of course, if a child has jaundice or hypoglycemia or some other issue that requires food right away, you may need to give formula, but I just didn't want you to think that there was a problem with your body. You very well could be able to breastfeed this next baby (for free!) if you wanted to. Some people have a hard time breastfeeding and some have an easy time, but if you're both healthy, there's no harm in giving it a shot. For me, my milk came in after about 3.5 days, and after a little over a week, breastfeeding was going great (it takes you and the baby a little while to get the hang of it, and the first couple of weeks are often hard). Since then, though, we've had perfectly smooth sailing. I'm not trying to push it on you, just letting you know in case you would like to try breastfeeding.
By the way, I just saw your update -- I don't understand. You're right taht some people don't produce enough milk. It definitely happens, although it's pretty rare. However, you couldn't know that in the hospital ... most people 's milk hasn't come in by the time they leave the hospital. If, after your milk comes in, the baby isn't gaining weight, then it's possible you're not producing enough milk. I'm not judging you, I'm just telling you the facts. Formula isn't poison (heck, I give my baby a little bit!), but breastfeeding is linked to lower rates of allergies, asthma, ear infections, and other illnesses; also, BF babies have slightly higher IQs. That DOESN'T mean that a FF baby will be sickly or have a low IQ, it just means that a BF baby has a somewhat better CHANCE at fighting off illness (makes sense, because they get mom's antibodies) and so forth.
As far as formulas go -- I think the three big ones are Similac, Enfamil and Good Start. A lot of pediatricians are hesitant about Good Start because apparently Nestle isn't forthcoming about all the ingredients in it (some people also boycott Nestle because of some really shady marketing practices where they've really taken advantage of poor, uneducated people). We give a few oz of formula at night and use Enfamil. But honestly, the thing to do is just to try one and see how it goes. I feel like most formula feeding moms have to switch once or more to find what works for their baby. I would also try either the Target or Walmart store brand, which is basically identical to the name brand. I don't think store brands have the equivalent of Alimentum, Nutramigen or the more specialized formulas, though. I might start with Target's hydrolized protein formula, which has partially broken down proteins, making it easier to digest.