A little liverock would help with biological filtration and also provide a little bit of material for the angel to graze on. PVC is cleaner than liverock for use in a quarantine tank, but it is completely sterile. If you are going to be treating the angel with any medications other than Prazipro, then use pvc, otherwise liverock would be better.
A hang on back filter or small protein skimmer would also be helpful, but isn't required. You will need a small powerhead to keep the water moving and oxygen levels up.
Good luck with your angel! You will love it!