I know the mags are not fully covered but with black mags this blackberry case would be farily unnoticeable.... a good place to find pouches that might work is a cell phone store...also, most hardware stores have a section with balistic nylong pouches of varying sizes for cell phones and tape measure and such...
also, check out knife sellers too...
Medium Lockblade Belt Pouch- Nylon/ Black - Pouches - Knife Accessories - Knife Off