I love Thinktank products, both their bags and backpacks. They have a new backpack, the Urban Approach 15 which is designed for mirrorless cameras. I personally have the Streetwalker which I used for my Nikon equipment, but having sold most of it, it now contains my X-T1, XE2, 14mm, 27mm, 18-55 zoom, 56mm, 55-200 and my new 50-140, along with my 3 Legged Thing Brian. It can also carry a laptop and has pockets for various accessories and a tripod carrier.
Here is a link to the Urban Approach: http://www.thinktankphoto.com/products/urban-approach-15-backpack.aspx