Wow, some people really are so judgemental. I'm sorry for the answers you're getting for questions you didn't even ask :(
My oldest child never took a bottle. She absolutely refused, but it worked out for us b/c I was able to be with her and nursed her until she was a year old. My second one I went back to work (and in conjunction with a host of other issues) when she was 7 weeks old and started suplementing her with Enfamil and she did fine. Her favorite bottles (which aren't even made anymore) were the Gerber basic ones. My 3rd child took only the Playtex nursers with the liners, and Enfamil formula once we started suplementing her around 8 months, but did ok with breast milk in the bottle before then. My son was a whole different situation though. We tried only with breast milk with every single bottle available for purchase with no such luck. Finally, I discovered the Soothie brand bottles. They have the same green nipple as the hospital issued pacifier, which is what he had. He took to that like white on rice :) Once he was used to that bottle, we were able to start giving him some formula (started with the Walmart brand, then switched to the Sam's Club brand).
As for figuring out which formula is best for her, I would talk to the pediatrician. They can give you samples of different kinds so you're not spending thousands of dollars on formula that will be thrown away ultimately. It may cost you a small fortune in copays to revisit every few days until you get it figured out, but in the end having the right source of nutrition that works best for her is worth it :)