Who Can Kill a Child? is due a UK DVD release in the very near future, however if you can't wait that long Dark Sky's US DVD is superb. This is honestly one of my all-time favourite films, it completely blew me away when I first saw it, and loses none of it's raw impact on repeat viewings.
As for
Carrie; we have a love/hate relationship.
I first read the book when I was about 8, and absolutely loved it (I've probably read it about 20 times since). However, I was very underwhelmed when I first saw the film, mainly because the book covers so much more key material (especially in respect to Carrie's post-prom rampage). On repeat viewings I learned to appreciate more, but it will never achieve the levels of greatness the book did when I was 8! The shock ending, which is not in the King book and that De Palma added to the film was a nice touch, though.