Pixelmon + plugins? Which software?

I want to make a Pixelmon Minecraft server that runs with the Complex Gaming Pixelmon Mod. But I also want to make plugins on the server, which software should I use? Forge? For info: I rent at McHost24.de

Spongeforge if you want to use mods and plugins. But what version do you have to look for yourself what Pixelmon is up to?

https://www.spongepowered.org/downloads/spongeforge/stable/1.12.2