I'd like to know about any 3D asset shops out there that specialize in game assets and, most importantly, license their assets under an open license like Creative Commons or similarly permissive.

We are looking to buy some professional looking assets for use and redistribution with our open source 3D game engine. The problem is that all the commercial 3D assets we've come by are only sold under very restrictive licenses, which won't allow us to include the models in our code repository (since free code hosting repositories require that all your data, including media, is open source or otherwise copyleft) nor in turn redistribute the assets as part of our downloadable SDK.

I realize this sounds like a weak business idea, since users could just buy the asset and start sharing it with everyone. But somehow this has worked for hundreds of WordPress theme shops, so I was hoping maybe someone's trying similar things for commercial game assets.