Since we tried to optimize the data load (only Diff maps that are used by multiple objects) and workflow, we now found a nice (and old) script for blender 2.49 that lets you bake the Ambient occlusion into the vertex colors. And it is even GPU accelerated! You can get it here
So this temple only consists of two objects, an arc with one pillar and one floor object. So it also only uses two textures, but still gets the unique look with AO in the vertex colors.