Try taking any quick name generator and narrow down the search to male names starting with L, or female names starting with S. That way, you can go through and find something that you feel fits the character best.
And even then, my advice would be to not restrict yourself to similar names. It can't be forgotten that characters don't name themselves - they are named by their parents at birth, before anything is ever known about them. Ludwig could become Dominic or William, and still be the same character.
Seventh Sanctum Quick Name Generator. It's based off United States census data, containing male and female character names. Ludwig is somewhere on the list, but every generation will bring up different combinations of different names. Have a bit of fun with this to see what sparks your interest.
Best of luck.