Where can one obtain these armors?
The Covert Energy armor is strictly Cartel Market, though people post it for sale on the GTN if they have no use for it.
Imperial Dancer armor is available from the Security Key vendors in the Fleet and at the entrance to Kaas City.
Republic Dancer is available from the Security Key vendors in the Fleet and in the...Coruscant Senate Plaza (I think).
Slave Girl outfits are obtained from the Social Vendor in the Slippery Slopes Cantina on Nar Shadaa. Social Level 2 is required to obtain this.