I'm so sorry about the diagnosis of your baby and the hardship and pain you are going through...
13 years ago, we had a daughter with anencephaly as well, you can read Anouk's story on my site (http://www.anencephaly.info/e/anouk.php). She was born at the hospital, but except the fact that we choose to have a medical induction at 40 weeks, pregnancy and birth went without any complication. Anouk was alive for 13 precious hours after birth.
Through the website I built after her death, I've been in touch with many other moms of babies with anencehaly. Homebirths are not common, but I can tell you that if at the hospital there is a 25% risk of stillbirth (see http://www.anencephaly.info/e/report.php), the 10 babies who were born at home I know of have all been born alive. I had a homebirth myself (for my 5th child) and think that the smooth way such births are managed are gentle on the heads of babies with anencephaly and this may protect them.
You can find a story of a homebirth here http://www.anencephaly.info/e/carmen.php and in our group on facebook https://www.facebook.com/groups/anencephaly.info/ there is a mom who is about to give birth to her baby with anencephaly at home (she's due any day from now). I'm sure she'd be more than willing to share her experience with you.
Babies with anencephaly are able to feel pain, but they are not in pain just because they have anencephaly. Most babies who survive birth are very peaceful, but few do have seizures. Usually, they are managed without medication, but you may want to check with your health care provider (I'm from Europe, so not familiar with your health system) to have some pain medication on hand for your peace of mind.
Is this your first baby? Births of babies with anencephaly tend to be very much alike previous births, but sometimes it takes more time.
Feel free to contact me through my daughter's page, I'd be more than happy to answer more questions.