Laminar flow is best, a gyre or such, lots of sand...6 inches? at least? open sand bed at least on one end, not so much rock. Definitely do research. A garden eel set up may prevent you from keeping certain other fish, corals, change your scape...
My LFS gets them often so it seems they are not rare... guessing most places just don't order them because of their requirements.
The tank needs to be a tank for them first... and anything else 2nd. A tank set up around this species. Feed a few times a day. I would buy several as they like to be in groups.