If you are going to be expressing a lot, it is worthwhile to get a good electric pump. Double pumping is helpful but if you are not exclusively expressing it's not necessary.

It is also worth noting that many babies just won't take a bottle regardless of when it's introduced, so getting in early might not be helpful, and can affect getting breastfeeding well established. My first DS drank from a bottle from birth as he couldn't attach, but once his tongue-tie was snipped and he could attach he wouldn't take a bottle at all! With DS2 I started him early for that reason but again he just wouldn't have a bar of it. The good news though is that babies can drink from a cup held to their mouths from birth, and from a sippy or straw cup from about 3 months, so bottles aren't the only "non-breast" option.