I'm leaning towards the Pack Vest by Patagonia. It has a mesh vest attached to a 1700 cubic inch pack which can both be used separately. The reason for a large pack is that I dress in layers and my small Orvis pack cannot hold the extra clothing. However, as Jim Simms told me don't get it or you'll fill it up.
I will then need a pack mule to haul my gear. FishHawk