Check out Tasmanian Tiger Tactical bags, they're a german company. I use the mission pack at work (1RCR) more than the issued day bag. The tas bags are decent priced and have held up to me stuffing belts of c6 ammo into it some days, and to carrying the 552 radio with extra batteries and supplies.
If you're humping your kit the whole game, you'll be surprised how little you really need for 12 hours.
You wont catch me eating IMP's outside of work, I usually pack beef jerky, nuts, and some gels.