I haven't yet found a good extract that I trust. I've used 6 different flavors across 3 different brands, and they all taste "medicinal" or fake. So far, IMO, they are only good when used lightly as a supplement on top of the true natural flavor. So, if you used coconut in the fermenter and then added a little bit of extract on top of that.
Or, do as squeegee suggests and make your own, I've had much better results with making tinctures than using commercial extracts.