I have used Ecosoya CB135, Ecosoya CBA, and C3 soy waxes. Personally I prefer the CB135. But it doesn't matter which wax use. Find one you like and work with it until you know everything about that wax before you move on to another.
Its not surprising that you are having issues with the 26 oz jars. Those are tough jars to wick in the first place with parrafin. But with soy you will have even more wicking issues. The zinc is not a good wick for soy alone. Additionally, it is going to be difficult and near impossible to wick a 26 oz jar without double wicking it. I never got the 26 oz wicked properly until I double wicked the jar and blended my wax to make a parasoy blend.
Its also not a good idea to sell candles when you have not got the wicking down. Once you have the candle properly wicked it will be more safe for the general public to use. So until you do I hope you have insurance for selling those candles. Not trying to rain on your parade. Just trying to encourage you to keep at it until you get the right wick with the right wax, jar, etc.
I don't do a straight soy wax anymore so I can't help you with the wicking. I custom blend mine into a parasoy and I do use zincs which work perfectly for my jars and wax blend.
A good place to learn more about wicks and how they work for what type of wax is to go to
http://www.wicksunlimited.comGood luck!