The most unkillable LPS are imo the frogspawn and the candy canes. You got them for real cheap, was there a reason for that ? Sometimes, questionable stores slash their price when their corals aren't in top shape, even turning them around to hide their wound/disease. With LPS you can't always see it all around, so beware. Acclimatation should be done slowly and LPS are extremely easy to puncture. LPS in a 8 gallon can be more difficult due to quick parameters changes.
I have a 120+ G. water volume so it's easier than a 8.