I exclusively expressed for my first two babies and it was tough going at times but I felt very happy with it.
The first time I did it because I'd had a csection and a huge baby and no support to bf at all and got a bit lost, but still wanted to give baby as much bm as possible. I got TONS of milk while expressing - filled my freezer and then some. I was able to wean him and cook with the milk and ended up chucking loads.
It could be hard to carry the pump, plug in and get time to pump but it was doable. And of course it meant dh or other family could feed baby, meaning I got out etc, which was a lifesaver.
The second time, because I'd felt so stressed the first time (lots of pressure to bf - man, the guilt was enormous!) and had PND, I was determined to do things my way and have more control, so I decided to go with what I knew and expressed from the start to lessen the guilt and stress of not being able to bf.
It was tough going with a 2 year old and a baby and I caved to formula at about 3 months this time. I'd had some hairy moments trying to pump with a toddler and a baby!
Third time round, believe it or not, I'm breastfeeding exclusively! I got a pump and decided I would formula feed if I needed to - it's my last baby and I was determined to enjoy rather than get stressed or feel guilty for anything. I didn't commit to whether I was going to or not, just went with the flow. Ds3 is now 7 months old and we're still going. It's mad! I never ever thought I would ever be able to, so it's a bit of a treat. I still pump occasionally to get a break. I even bought a wee bottle of formula last week and a bottle of wine and my dh fed baby while I had a drink - it was great. I think the thing I have learned most is that it's best to just chill and enjoy. I put far too much pressure on myself with my first two and it made me ill.
I would say get as good a pump as you can afford. I have a Medela swing and it worked just fine for me, but the hospital one I used was amazing.
Lots of bags for bagging up milk. And a sharpie for dating it!
Reuseable bamboo breast pads were great in the early days.
With expressing I found there was a slight 'need' to milk off more than I get with breastfeeding. With bf, the milk doesn't seem to be there now until baby needs it. With expressing, I did feel a wee bit like a cow - sometimes it made me feel funny until I had gotten rid of the milk. And it was time-consuming but I worked it out. You get into a routine just like any other.
You'll get people who question you and claim bf is easier, but if it's what you want to do and it works for you, tell them to bugger off. Definitely seek support on fb etc. I was too early for any of that and it would have been nice to have the support rather than all the negative comments. You have your resons and you should know they are good enough - at the end of the day you are the one living your life, nobody else has to.
None of this is probably useful, it's all completely anecdotal!
I suppose all I want to say is please don't put too much pressure on yourself - if you find it too hard, that's okay. Nobody is judging you. Every day baby gets bm is a bonus and it's really not the end of the world if you need to stop/supplement. Keep yourself happy. And good luck! Hope it goes well for you :)