The Lowepro bags come in at an excellent price point and nice quality, but their feature set is definitely geared towards camera equipment and were not designed for running audio equipment. I would check out Kata or Petrol if you are not interested in Portabrace. I'm not sure you will find a Lowepro bag that meets you needs.
I recently went on the hunt for a new bag. I tried 3 Petrols, 3 Portabraces and both Kata Sundos and none of them worked for me.
The Lowepro Magnum 200 AW is perfect, though