Models are better to download in one stream only.
If the download process is interrupted due to a poor internet connection, use a free downloader program, such as Flashget
To reduce file sizes, pack all models in archives.
Before using the model, you need to unpack the archive. Use free Winrar app for this.
After unpacking archive, move all the textures into default folder with textures, then import the model into the scene
Important: the units in your scene must be in millimeters