Having an eel is pretty awesome. It's quite a rare and exotic pet to have.
Before you go out and buy the little shit, please go read up on the internet of how to care for it and what conditions it needs.
Looking at how you are currently stand in the world of aquatics, it doesn't seem like you know much... and trust me, there's a lot to learn.
The last thing you want is for the eel to die because of your lack of knowledge. More so, it's unfair for the eel if you were to bring the creature into a tank and it pegs within a few days/weeks.
If you're really interested into spending a lot of time taking care of your pets/creatures etc., you should start researching saltwater aquariums. Definately the best hobby one could take up.