The last time I needed to do an "easy out" operation I went to our local dedicated tool store (vs. the tool section at home depot, etc.) and they had a complete selection of left hand bits so just had to buy the correct size based on easy out recommendation.  In the case it was a broken cyclinder head bolt and it backed itself out nicely as I put pressure on it so the easy out wasn't required...lucky dog I was!  :)

 

Doug