When it comes to bottles, you have many options.
There are the traditional narrow bottles with small nipples, or you can get wider bottles with wider nipples resembling a mother’s breast.
If you choose normal bottles of any shape or size, you need to sanitize them, at least for the first 3 months. You can do so by placing them in boiling water or buying a sanitizing machine.
Normally for newborns you need the small 4 oz size and as they grow you can switch to larger size (9 oz).There are many claims in the market about bottles that reduce colic, or air bubbles. Between sanitizing, making formulas, feeding your twins and changing diapers, you won’t have time to do anything else. To save some time, there are also bottles with disposable liners. After feeding your babies, you just get rid of the disposable liners and wash the nipples and rings in hot soapy water. (According to the Playtex instructions). This option can be a time saver but these bottles are pricier than your normal ones. Playtex has a good system with a beginner kit.
Regarding the shape of the nipples, at the end of the day, your little ones will decide which ones they prefer!
You still need to boil water to make formula for the first few months. But you can make a few bottles that will be consumed in one day ahead of time, pour it in the Playtex bottles with liners and keep it refrigerated. To warm the bottles you simply place the bottom portion in a bowl filled with warm/hot water for a few minutes. Do not place the bottles in micorwaves.
For the first few months, we used Playtex Baby Drop-Ins Premium Nurser Newborn Gift Set. We have been very happy using the liners. It is very easy to use, saves time, but a bit pricier than normal bottles. Once we did not need to sanitize bottles or boil water, we switched to Playtex Vent Air (US) or Avance (Canada) bottles that reduce air intake with a wide top.