The pearl choker unfortunately can't be bought. It's selling value is $1000, so without premium I would say you can find it at ambush stagecoach, bounty hunter, grave robber, with higher income premium probably peace negotiations also.
The umbrella is just an idea, proposition, so far. It is taken in consideration by the game developers and it is possible that we will have it soon, but is nothing certain.
As the gentleman's set has the walking stick with the charisma bonus (giving male an advantage of 2 AP females can't get), the dancer's set might have as product the umbrella with a bonus that could be worn all the time. We shall see what will be! I want that umbrella too. And the choker (still didn't find one, but found 2 walking sticks) ...