I've been little off line lately and came acros this screenshot... How to play it off line single player?
You can see most of the key stats in the screenshot, but you'll need either the mod that relaxes editor limits, or to export-modify-import a planet file in order to get the extreme height. The harder part is actually playing it; you'll have to hack your server-script/sim_utils.js to raise or skip the height restriction, then cross your fingers and hope it isn't checked again in the engine.
Via the system editor you can save your system in a .pas file. Others can open this file ingame and then they also have that system in their system library. For example: https://forums.uberent.com/threads/i-bring-you-hot-platforms.66831/ You can download the zipfile which includes the .pas file. When you open it ingame you will have the system
Mod wise, System Sharing has a whole bunch of systems in it. Only issue is that the choices are rather overwhelming.
Once Asteroid belts are out, Im sure someone will spend hundreds of hours making a perfect duplicate of our Solar System That will be a Shared System Id even BUY right off the bat Xd