There are various archives available at this site.

• Quake Singleplayer Maps/Mods at http://www.quaddicted.com/reviews/
• Quake Multiplayer Maps at http://www.quaddicted.com/files/maps/multiplayer/
• Quake Engines at http://www.quaddicted.com/files/engines/
• Quake Texture Wads at http://www.quaddicted.com/files/wads/
• http://www.quaddicted.com/files/ has some more
• Random Quake and remotely Quake-related websites and archive mirrors at http://www.quaddicted.com/webarchive/

You are very welcome to mirror these. If you need help with that, ask in the forum. You can also ask Spirit to burn you a DVD or CD and send it to you (if the files fit on it). The webarchive directory is huge (108 Gigabytes at the time of writing) and there are redundant files, you better do not blindly start mirroring it all. It also is quite a mess.