I designed an SSTO that uses an Orion engine which can easily land on any planet or moon in the game. It has a docking port and RCS thrusters which enable it to dock with space stations. I edited the .cfg file for the inflatable heat shield to make it able to deflate, so that the what SSTO can even land on & return from EVE. It has an ore tank and an ISRU that has been modified to also create fuel for the Orion engine. I use Ubio Welding to prevent my FPS from dropping (Great mod fyi), so make sure to copy that file if you want the craft to work. By the way, I know that using the Orion engine kind of defeats the purpose of an SSTO, but it's still fun. Below is a link to my KSP Google Drive that has the SSTO file, screenshots, and my entire game data file. If you like it, check out my youtube channel because I am getting into making KSP videos. I will post a video from my channel at the bottom of the page.
Google Drive link: https://drive.google.com/drive/folders/0Bw3KHaJbImtPOEpreHNQdkVkVE0?usp=sharing
Pictures:
As I mentioned earlier, here is one of my youtube videos: