With soy waxes you need a wick with high liquid flow characteristics. Some popular wicks that have these characteristics are CD, Cotton, Eco, HTP, LX, and RRD. I think choosing a wick is a personal decision based on how you think/want a wick to burn. In my observations, the wicks that people talk about the most here on the Veggie board are CD, LX, HTP and RRD. I would suggest getting sample packs of HTP, LX, and RRD wicks. This will give you an idea of the range of different wicks our there. When you ask for help on wick sizes, you need to give some information to help us give suggestions. That information is what brand of wax, additives such as beeswax or paraffin, type/amount of FO (fragrance oil), and diameter of container opening. You should also include what type of wick you looking use if you have one in mind.