REI stores have good stuff that you can pull off the shelf and try. +1 on that recommendation. Look at their supply of Osprey and Arc'trex they, come in more civilian coloring and hold up well.

For years I EDC a Bug Out Bag brand (BOB) backpack. it is very close to bombproof, trust me, I destroyed it. its a cross between an assault pack and a day pack so lots of dedicated areas for pens, laptop, hydration, descent sized main pack. I used it for business and personal EDC without a second glance. I use a GORUCK GR1 now and probably wont buy another day pack ever again.

I would stay away from 5.11 bags. Say what you want on their other gear and clothes but I have destroyed there Rush 18 and Rush 24 packs in less than a month. I mean to the point of unusable.

I also recommend Mystery Ranch. They make outstanding packs, more than you would ever need for durability and adaptability.