Hi there and Congratulations!!!!!
I am having twin bliss right now, and there are moments with twins that are so tenderly sweet, you won't believe it. And don't worry, I think most everyone here FREAKED OUT when they learned they were having twins.
For our family, it meant a huge change in income, and I worried a bit about the sleeping thing, and the car thing, and the attention to DD1 thing. But I'm here to tell you that it all worked out. I think the secret is to accept all the help you can get, and all the gear that anyone will pass to you. But in the end, my girls used the swings maybe 10 times, and almost never went in a bouncy chair, and we put 2 infant seats and one toddler seat in the backseat of our Toyota Camry. Just a month ago we got a minivan only b/c the Camry had transmission problems. Eventually we had to get the minivan to accomodate 3 toddler seats, but, we could have done it for at least one year.
Cosleeping: we did it and still do it. At first, (during pregnancy), I got DD1 to sleep in her room w/me. After the twins were born, she spent a few nites in our bed and decided it was not a good night's sleep.
She then came back to our bed, which was good, as I was tired of running room to room for the wakeups that ensued. We put a twin mattress next to our Queen, and though it is always changing and never perfect, it's fine, and sometimes even perfect. As far as the pack and play goes, we just use the mat from it on our hardwood floors as a soft place to put the babies. We cloth diaper them (even cloth wipes), and I've never pumped. There are benefits to pumping, and you may need to, depending on your situation, but I HATE pumping and can't bring myself to wake up to do it.
Just wait until your twins hold hands when they nurse, or when they see eachother and just giggle like old friends. It is sweet, it is beautiful, it is so freakin' hard at times, but also so great. Twins are also the perfect excuse for not getting anything done and needing a lot of help.
One of my dearest friends did buy us a freezer to put in our attached garage, and that has been a godsend! It allows us to store lots of food. (great for the ever hungry mama!)
As far as birth and breastfeeding go, as with all birth, you never know what you will get, and what life lessons are to be learned from your experience, but if it cheers you any, I had my twins at home and breastfeed them with ease right away. DD1's birth and breastfeeding did NOT go like that, and so I felt delighted that with twins, it all went easily.
Good luck, and hope to see you on this board again, as there are a lot of fabulous mamas on here just waiting to root you and your family on.