Install a ModernCraft (Distant Horizons) server through the Control Panel (Servers → Select your server → Game servers → Add Game Server → ModernCraft (Distant Horizons))
Honestly, I haven't played Minecraft since I was 15, but for a friend's party, I decided to use a proper paid server to ensure a stable connection. Plus, I was looking for a service with a really easy interface, so I wouldn't have to figure out how to set everything up.
I can say that ScalaCube is a great option. Thanks!