I'm glad to see you are going with Ogre3D. It's a good engine.
I wouldn't worry too much about the models. Just get a nice one or so for the distribution, especially if they will let us texture them.
There are plenty of good, free modeling programs out there like Blender, that will let us make our own models, and Ogre has a converter to let the blender .XML files be changed into the Ogre .mesh binaries. I bet it won't be two weeks before custom models start popping up.

I think there are some people on the Blender3D forum that would make some for free just for the fun of it. Blender also has a few automated human making plugins like "Makehuman" (
http://makehuman.blogspot.com/ )that would mean somebody could turn out a model in hours, and have it ready the next day if they knew how you needed it rigged.
Just a thought.