I think all the Hi-Poly models are added to the media VP:s, and there is no site that has all of them separately... as far as I know anyway...
Though some models may also be available "beforehand" the release of the actual media VP content.http://scp.indiegames.us/download.php
MV_models is the file that has all the Hi-Poly models currently available
If the Hi-Poly models are released beforehand, then they're place will be at data/models folder.
If any maps are involved with the release then they will go to the data/maps.