Tech-based Loli-Bag Question

I'm always finding myself looking for a decent-looking, strong bag to hold my laptop in while I'm out to a coffee house in classic or casual. Short of making myself one, are there any bags large enough and strong enough to hold a laptop in?

We're not talking an Acer e-book, but a fairly sizable laptop and its accessories, about 10-15 lbs worth of stuff. I was looking into suit-case style baskets or bags as a result.

My laptops measurements are 38-39 cm by 27 cm, with a 4 cm thickness when closed.

Pockets would be nice, but I'm not opposed to having to sew them in myself. Anyone got any ideas? Can anyone chime in on the strength of certain bags or cases that they own?