I can't really recommend a palm substitute for you, but I would recommend that you look at the 'sort soap making oils' page on soapcalc.net, there you can check palmitic and a whole list of oils containing palmitic acid will come up: the ones I often see recommended as subs for Palm are on there: shortening, cacao butter, rice bran, avocado.
I'm wondering why there is no olive in the recipe, and notice that your coconut is high, has a figure of 27 on soapcalc, quite far beyond the range. I know there has been recent discussion on the forum about the numbers on soapcalc, the hardness of water in one's area and one's skin sensitivity levels, so for me I'd say that this recipe, with the soft water here would dry my skin terribly.
I'd also like to make another plea for Palm oil. Yes palm oil from Indonesia is unethical, yes we can't often trust corporations to police themselves. But other places do produce palm oil. If you can find palm oil from Costa Rica or Nicaragua, it comes from plantations that were previously banana plantations or pasture. Banana plantations are fairly toxic, and pasture is neutral at best, palm plantations may be mono-cultures, but they do create habitat and the trees are better for the environment than either banana or grass.
I know emotions run high around here on palm and the tallows. And I understand that there are a lot of soapers who have done their research and are passionate. But if you can find palm from Costa Rica, your substitution problems could be over.
