Custom backgrounds

I was wondering if it’s possible to assign custom body background images for each page separately? So for example I would have backgroundX.jpg on home page and backgroundY.jpg on blog page? Of course I have boxed version of theme in my mind.
The second question is about logo. I need to use 3 different logos assigned to specific pages (imagine that website represents 3 small companies). I guess your theme doesn’t support that feature by default? Do you perhaps have any idea how to implement that, would it be hard to do it?
Thanks!