Bless you, you are being really brave to look at how you feel and find information to help you do what you think is the right thing by your baby.
People have expressed and bottle fed. I guess it is very very time consuming as you effectively have twins who are not in a routine - you are feeding the pump, and then the baby. You will need to express very very regulary, especially in the first weeks. I'd have thought 2-4 hrly as that is how babies breastfeed, and you are looking to try replace the baby with the pump. Which with feeding 2-4 hrly will mean you are on a very strict busy regime. I haven't experience of that however, so maybe someone who has done it could offer you some insight into what you would be looking at in terms of work. I'm woried you won't be able to leave the house for more than an hour for weeks!!
I think we imagine breastfeeding to be 6 months [or 3 months, or 3 years, or whatever] just like the very early days. When 8 cushions, 3 cloths, a bottle of water to drink, 3 shals to cover up and a breastfeeding bra are required. ANd for many, the first few weeks, maybe 2 months, can be like that.
However, when the baby grows and is stronger, able to move their head and sit on you knee easier - it is sooooo much more a case of lifting your jumper a bit and popping them on. Honestly.
I have G cups, and a belly to match, and I bf in public without a single bit of flesh on show. Although not in the early days when she was tiny.
I'd compare it to driving. In the early lessons parking was a nightmare and took 20 mins. After a few years of school runs and busy supermarkets, we do it with the radio on and don't notice when we bump a porsche.
A belly band is brilliant. It covers up between the top of jeans and bottom of top, so no belly or back flops out.
Good luck with whatever you choose to do, and congratulations on your baby. Whatver happens with feeding I hope you have a lovely pregnancy and a great time with your new bubba. Exciting!
P.S. Find your nearest breasfeeding cafe. Utterly brilliant.