I am looking for a bag that I can fit inside a backpack. 12 inches wide max and I'd prefer if was a bit less and probably around 5 inches deep. Something that would hold a body with lens attached plus room for 2 more. I'm thinking a messenger style might work, something where the top flap is held by Velcro, not a zipper as it seems I am always fumbling to get at my gear. I'm currently using an inexpensive Lowepro Rezo 170 which is just barely big enough but does work okay. Around $75, any thoughts? Thanks for any recommendations.