I am working with some 3 1/2" containers with the Ecosoya Advanced soy wax and am having luck with the HTP wicks, the 1212 or 1312 might be a thought. Peaks sells a nice sample pack. So far, most of the suggested wicks I've seen on website (even the Candle Science wick calculator) seem to describe paraffin burns and not soy (even if they say so). I have not checked everywhere. For me, the best idea was to get the sample packs have at it. For a large candle like yours, doing melts and re-pours sounds tedious so I'd consider pouring with no wick, insert a needle and make a hole when cool and just insert your test wick (no bases) and burn for a while. If it is no good, pull it out and insert another one.