Until now what I ound was that the google warehouse has tons of models and most of them you can chose the format, not woe much options, only two: skp or dae.

The kmz option is not an option because it has a dae inside and we are back to the only two options. The dae format is a collada option that can be opened by many applications, MeshLab for example.

As for the skp format itself I think that will not be too much problem to make an obj converter. Until now I found that inside a skp file are the textures, some png file that I think that can be the thumb of the model and something in xml, maybe is the geometry in dae format?

Stupidity also evolves!