Emulsifiers: What’s a complete or all-in-one emulsifier?

I found a comment from someone who was having trouble with lotion separation. In the message, she notes that she is using the base emulsifier from Aromantic in the UK. This is not a complete emulsifier – it’s glyceryl monostearate, a low HLB emulsifier that must be coupled with a high HLB emulsifier to create…