Great Topic Poppy. Like some others have said, I'm sure some providers don't want to post for fear of alienating potential new clients. I'm sure they want to see what a certain hobbyist is like based on his posts. There are certain providers who have a style of writing I prefer. Then there are others who's lack of mastery of the English language send me in the other direction.
As far as providers which peek my interest based on their style here on the board, I'd say the following meet the fantasy criteria. I should note, I have not seen any of the ladies yet which adds to the allure. I may never meet them since I'm a creature of habit and like familiarity. Lastly, being they are beautiful women absolutely helps enhance the fantasy.
Heavenly Hayden aka Hayden Hightower
Carrie Hillcrest
Kelly TNT
Reese Foster
I'm sure there are more, but it's late and I'm getting old. So ladies don't shoot me if I left you off.
FTH