There are many places. What jars are you using that you need a replacement for? Most candle suppliers also offer jars, it's just a matter of the jar you want.
I currently use these: http://www.jarstore.com/jars/12-25-oz-libbey-vibe-jar/ with their rustic lids but they have discontinued those lids. My candles really stood out with those lids and am looking for a candle jar with a lid that stands out.