Damn man, that is a tough one because if you are saying prodomme, I think sessioning is within reach already. Even dommes like Goddess Tangent, you'd be surprised to know a session is within reach. So if we're talking pornstars, probably someone like Lexi Sindel or Ashley Edmonds as I don't see any indication they do sessions outside of filming.

As far as an actual session if I had a free session from a lottery, probably one where you have multiple well known pros, most likely in LA as they have the hottest dommes, but you'd have multiple dommes, female slaves in the same room and other session sounds that you could hear from other rooms while your session is taking place.