Welcome to the Unstable SMP Mashup!
This modpack has everything that Unstable has to offer including, Orbital Strike Cannons, The Farlands, The Great Sea, The Mist, Spokelands, Underworld, Unstable death sound, and so much more that I can explain down below!
Orbital+:
It includes:
Orbital Strike Cannon
Orbital Wolf Cannon
Stasis System
Railgun System
For the list of commands on how to get the orbitals: https://www.curseforge.com/minecraft/mc-mods/orbital 
This mod also includes the death sound of Unstable, A proximity message system and you can config your orbitals exactly the way you like them by using /oconfig rod vanilla or /oconfig rod unstable.
Unstable Generation:
This terrain generation mod mimics Unstable SMP’s world generation. It adds Amplified (62,000 blocks away), the Great Sea (300,000 blocks away), the Farlands (12,550,821 blocks away), the Underworld (below the Nether), aswell as The Mist (Roughly 100,000 blocks away).
The Farlands:
The Mist:
The Great Sea:
The Underworld:
Mod Link: https://www.curseforge.com/minecraft/mc-mods/unstable-generation
Planning to make a server out of this modpack so stay tuned! Sharing this modpack and writing suggestions or bugs in the comments helps me out a lot! So what are you waiting for? Go become a protagonist for yourself today!