Hi! I think MP soaps are fun and honestly - you can get so much more creative with them.
The SFIC bases are the best and most natural. They are the closest to CP soap you will AFAIK.
Peak carries them - but I know several others do too. They are close to me so I order from them. Their ingredient list for their Goat's Milk base is the following:
Ingredients: Coconut Oil, Palm Oil, Castor Oil, Safflower Oil, Glycerine (kosher, of vegetable origin), Goat's Milk, Purified Water, Sodium Hydroxide (saponifying agent), Sorbitol (moisturizer), Sorbitan Oleate (emulsifier), Soybean Protein (conditioner) and Titanium Dioxide (mineral whitener).
Hopefully others can chime in with a list of other suppliers. I think it's been talked about on the board before.
Have fun!