Since the workload of the Sicilian or the KID may not be to everyone’s taste, here is a repertoire based upon the French. I picked the Slav to go along with this choice, because they are consistent with the basic concept of keeping the symmetry. It should be obvious that I can’t offer a magic bullet, so this should to be taken with a grain of salt. Note: This does look like a mess, but there is a download-button. You just need to edit the file and add the pgn-header and footer.
Note: In recent correspondence chess every game in this line ended in a draw. The line is safe, but not trivial over the board.
Here is the catch: If your opponent knows all this, he will not go for the mainline. On the other hand you have to memorize it nevertheless, because you shouldn’t allow him to catch you with your pants down. Recently both Aronian (vs. Vallejo Pons) and Grischuk (vs. Shirov) attempted to do just that. Against weaker opponents you are running the risk to allow a forced draw, so this may not be the best way to maximize your chances. This line is a double edged sword, but so is playing the Marshall Attack.