Totally outside your budget indicated, but I find the go ruck bags to be extremely stable. Buy once for life type of bags.

That being said I would recommend any bag where the designer removes the metal zippers so they don't jingle and instead uses paracord or something else quiet. And not the bags were they wrap the paracord inside of the metal zipper because those still jingle. It's just my mental litmus test to tell if the designer actually cares about the use of the bag, or if they only care about the looks of the bag for selling it. So far every time I've seen a bag without metal jingly zippers it's been a well designed and well put together bag, you can tell somebody cared and loved for that design