Re: Who would be most compatible with a Sagittarius sun and Scorpio Moon?
That has nothing to do with their sun and moon sign and everything to do with their seventh house and the gestalt of their chart. Even then, what the chart describes isn't the astrological placements of compatible partners, but, very loosely, what kind of personal characteristics they would have. That's true no matter what kind of partnership you're looking at: business, romantic, client/practitioner, etc.
And even then, different partners might manifest those characteristics in different ways.