The best option I think would be a Lowepro 250 or 350 depending on the size you need. (if you dont need a laptop bag get a 200 or 300).
The reason I didn't buy these for my camera kit, macbook and misc such as headphones and sketchbooks is because they were not totally suitable for A4 books as such. - or the style I wanted.
So I have bought a North Face Base Camp Free Fall backpack.
It is 21L (hot shot is 30L).
Has an incredibly durable and waterproof material (base camp material). although zips are not waterproof.
It looks nice
it is top quality with 2 yr guarantee
I use the large space for misc, laptop and other stuff and the smaller front pocket for dslr and accessories. It works really well am I will try and get a photo for you of how the dslr fits in (in the compartment the north face websites image is showing as a map pocket

I also stuck a little padding in the zip compartment outside the "map pocket".
Ive been looking for ages and really happy with it!.
If your really bold go for the yellow

I got black
LINK:
http://uk.thenorthface.com/tnf-uk-en/shop-by/activity/base-camp-free-fall-backpack-6.html
also check out crumpler, lowepro