Floating plants are essential with spiny eels. They stop them jumping, and the eels will "burrow" into floating plants and lurk there, which is very cute. If you want to breed them, then they lay their eggs in floating plants. Hornwort, Ceratopteris, pretty much anything large and floating will do.
Try also and identify your eel, as there are several species sold as peacock eels. The most common is
Macrognathus siamensis. It is pale pinkish brown with a pencil-line thin cream stripe running from the head to the tail. It has a few dark eyespots on the dorsal fin. It is quite sociable, and if you want to see it settle in quickly, get at least three so that they can hang out together. Provide a reasonable number of caves, so that they can be on their own if the want to. Provide silica (silver) sand for digging into -- never gravel.
With small spiny eel species, gravel is a death sentence. Macrognathus siamensis gets to around 25 cm in aquaria, and while it will eat neons and potentially something as large as a female guppy, it is completely safe with swordtails, rainbowfish, and other fish of that size.
Cheers,
Neale
one last thing, what sort of "habitat" would they benefit in most? I know i need sand as substrate but what else?