I am not fond of the idea of a centerpiece fish. Virtually all fish are social and do better in schools or shoals. To put one big fish in a tank as a centerpiece is maybe not cruel, but inappropriate, in my opinion. For dead flowers in a vase, that's fine, but not fish. A couple of angels or gouramis would work. Pearl gouramis are peaceful and attractive. But at least 2 or 3, please.