Dear Mr Fell-of-the-truck:
I don't know what your line of business is but the "best" choice of any gear is mission-dependent? If you're in law enforcement than either the TAC-V series from Eagle Industries or the Omega series from BlackHawk will serve you, you can load 12 fully loaded mags in both of those. If you're military than you can choose the above or any number of fine LBEs out there, check out Lightfighter.com. If you are a civilian shooter preparing for the end of the world, again the above will probably fit the bill. However, if you plan on fighting with full kit you better train with it. 12 magazines weigh 12 pounds, add water, a pistol maybe, some pistol mags, a combat/utility knife and you now have 25 pounds. Don't always think about packing the maximum load, light is usually right. Cache the rest until you need it. Some minor thoughts on the subject...