To get Tanyas costume u have to do one of the two outcomes to her mission. U can either get her a map, (u dont actually need to give her the map for some reason) or talk to Liu Kang in Lei Chen after she tells u to find the map. Once u have done one of those, she will appear near the portal at C-2 or C-3. Fight her there and win and you should get her costume. I had to fight her twice. (You also have to have unlocked her for Kombat by finding her in a chest in the Ice caves A-3 at 7pm-12am)
Sindels' alternate is found in a hut at H-6 in Outworld. This area is near where u meet Frost. Again you have to have unlocked her first.