Finally, caught the last one as I arrived at work this morning.
You should hopefully get Dark finished today Tiffany, Purrloin seems to be spawning quite frequently.
Make 3 Excellent Throws in a row rewards Gible if you can find that task. Your local Pogo community might be posting when Gible and Noibat spawn, we've been messaging each other when spawns have been sighted. Although still pretty rare we seem to have been averaging a few reports a day recently.
For Ghost i've noticed Gastly seems to spawn on an morning / evening between events which affect wild spawns.