I've recently become enamored of Red Head stretch jeans (relaxed fit) from Bass Pro / Cabelas. Inexpensive, but they fit well and seem to be durable. Front pockets are large enough for a small 9mm handgun. Oh, they do run a bit on the larger size, so you might need to go down a size from your "normal" size.
My Carhartt work pants have nice large (and extra durable) pockets as well.