There are no programmers out yet for the 2013, you will probably have 2 choices, Diablo and Bully Dog, they are both saying they are close to a release but we all know how long that took for the 2011 and 2012's, Do a search on the site for tuners and you will find lots of info on them.
There were rumors about both Diablo and Bully Dog having the 2013 tunes out in mid-April. Obviously that didn't happen. Hopefully soon though but you never know. Tunes for the 2012's didn't come out until the end of the year I believe. Might have even been January 2013.