First let me say that I've never made MP base, but I found this thread that may give you some pointers. https://www.soapmakingforum.com/threads/mp-from-scratch.78585/ I don't know what your soapmaking experience level is, but it does sound like MP from Scratch is an advanced skill.
In the past, I have used SFIC soap bases for MP and have been very pleased with them. They do have a goats milk one.