Oh, how exciting!
You seem to be doing very well with the shock of it all! I found out at six weeks, and can't imagine finding out so close to the actual arrival date! You don't actually need two of everything (if people are telling you this). The only things I found I really needed two of were carseats and slings. But, still, the adjustment to two babies from one baby is HUGE.
That's great that both babies are head down. Do they seem to be moving around a lot still (i.e. flipping), or have they pretty much settled in? It really only matters that Baby A be vertex. A breech baby B is the best kind of breech delivery that there is. Both of my babies were breech from about 28 weeks on (actually, Jasper (baby B) flipped from breech to transverse and back up until the end). I ended up with a c-section, which was devastating to me since I had wanted a home waterbirth. But, when I first got pregnant, I was lamenting to my acupuncturist about how my midwife wouldn't assist me due to the twins. He calmed me down and pointed out that I didn't get pregnant to have a homebirth. I got pregnant to be a parent, and what mattered most was what happened after the babies came out, not whether or not they came out in the hospital or my bedroom. So, I changed my focus to hoping for healthy babies.
I'd say that if you get to have a vaginal birth that would be wonderful regardless of where it takes place. Even if they make you deliver in the operating room. I *wish* I could have at least gotten the chance to push my babies out!
My babies were born at 38 weeks, 2 days, and weighed 8 lbs., 7 oz. and 6 lbs., 4 oz. They were both very healthy.
Be sure to check out some of the threads about breastfeeding twins. I wish I had done more research before my guys were born. They are EBF, and it's going great now, but the beginning was anything but easy. Also, "Mothering Multiples" is a great LLL book that you should definitely own.
Get some rest, mama, and keep those babies growing a few more weeks!