Aurebesh:
http://starwars.wikia.com/wiki/AurebeshAurebesh was a writing system used to transcribe Basic, the most used language in the galaxy.
Derived from the first two characters- Aurek and Besh.
In layman's terms, Basic is pretty much the equivalent of English, and Aurebesh are the characters used to write it so you straight substitute letters etc.
Now when you are talking about the Code of the Sith there's kinda two:
The Code of the Sith, known as Qotsisajak in Sith, was the mantra that reinforced the core beliefs of the Sith Order. It was considered the dark side counterpart to the Jedi Code, and was first authored on the planet Korriban in 6900 BBY by the Jedi heretic Sorzus Syn. The code remained remarkably unchanged through the millennia, as the Sith Lord Darth Bane still taught the words of Sorzus Syn when he began rebuilding the Sith Order around 1000 BBY, after the Seventh Battle of Ruusan.
The Sith Code, as written by Sorzus Syn[1] and taught by Darth Bane:[2]
Peace is a lie, there is only passion.
Through passion, I gain strength.
Through strength, I gain power.
Through power, I gain victory.
Through victory, my chains are broken.
The Force shall free me.
There also existed a version of the code in Sith, known as Qotsisajak—literally "Way of the Sith doctrine":[3]
Nwûl tash.
Dzwol shâsotkun.
Shâsotjontû châtsatul nu tyûk.
Tyûkjontû châtsatul nu midwan.
Midwanjontû châtsatul nu asha.
Ashajontû kotswinot itsu nuyak.
Wonoksh Qyâsik nun.
http://starwars.wikia.com/wiki/Code_of_the_SithAnd when you then start using the Sith language:
Peace is a lie, there is only passion.
Nwűl buti zo tash, ilsir tik shâsot.Through passion, I gain strength.
Pro shâsot, Nu gauti tyűk.Through strength, I gain power.
Pro tyűk, Nu gauti midwan.Through power, I gain victory.
Pro midwan, Nu gauti pergaleas.Through victory, my chains are broken.
Pro pergaleas, nuyak itsu buti kots.The Force shall free me.
Akuyi sekleti won nun.(
http://starwars.myrpg.org/coruscant_translator.php)
As you can see the way of the Sith doctrine would be a more correct way of writing the Code, probably with sentence structure correct to the language- bit like if we try to write a foreign language into English, we miss nuances, meanings of how certain words and phrases go together, how to correctly write certain things. The language translator literally translates word for word. Course as with any translator they are only so good- translate from basic to sith then back to basic and it'll be somewhat garbled.
Course it all depends- are you wanting to have it written in the language of the Sith which was originally the native language of the peoples of Ziost and Korriban and adopted by the Sith Order, or do you just want to translate English (Basic) into Sith symbols for the English words?