Can anyone recommend a sturdy LV bag/tote to use to carry books/papers?

For School, I use the daimer saleya in the mm. The thing that I love about it is that I don't have to use it just for school, I can use it to travel, as an everyday bag or whatever.
 
I use Damier Hampstead MM for a work bag and I love it, can be used on the shoulder or as a hand held tote.
I always have it full with books, water bottle and the day's lunch.:tup:
 
i just got a neverfull and I asked the SA about how much it could carry. she said that LV did a test and it held a ton of stuff ( i dont remember the exact amount of lbs, but it was A LOT!)..so i wouldnt be worried about the handles breaking
 
I'm thinking of the neverfull now. The price is really decent and I like the look. I want to put a laptop and some books in it as well.

What is a good size then? I want to be able to also use it as a big purse without it looking too strange. Would the PM, MM or GM look better do you think?