Tekkit Classic Minecraft Servers
Tekkit Classic is the original Tekkit game mode which is an extremely popular pack of mods which focus on automating, industrializing, and powering your Minecraft worlds.
Can't find a server that you like? Maybe it's time for you to create your own so you can make it exactly how you like.
If that sounds interesting, visit Gameserverkings. They can host it for you and help you set it up.