Mods Where can they be accessed?

@sumeee well, Infinite Fuel adds no consumption versions of all the engines and rcs and we are about to publish the first version of Real Engines
There's also a mod that adds dV, twr... and it existed before that data was shown in the game

There are no mods for this game right now. The posts that you are referring to are just changes to XML files. They don't add anything new, they just modify some craft or planets parameters (parameters that are not exposed through the game UI).