It's a lovely quilt and yes you can get black batting, though you may not have as many options in the types of batting.
Backing, I see a white and black print ... more white, to give some brightness.
And if you have a sense of flair and drama ... I would go for a bright coloured print, with s ome black in it, or a black background to it.
Take a look at this quilt of mine, and you'll see a fabric I think would make for a lovely backing!
http://www.quiltingboard.com/t-122204-1.htm