I store eels using a simple, cheap method that works great and have found no better.
1) Go to Home Depot and buy a new 5 gal paint buck with locking lid. (these are great! you should buy several)
2) get a 3/8 in drill bit and drill a series of holes all around the entire bucket , top and bottom and sides. (about 50 holes all together)
3) Find a rock the size of a grapefruit.
4) insert Rock in paint bucket
5) Tie a line to the handle of the bucket
6) Insert up no more then 50 eels per bucket.
7) Put lid on bucket
8) put eel bucket in the water next to a nearby dock or convienent retreval place.
This has worked for many years for me and the total cost is about 5 bucks. It has kept eels alive for over a year easy, without any food. I found that very few will die. The few that do get eaten by their roomates. I have 3 doz at the end of my dock right now. One year on block I had 200 eels in 2 buckets without any problems. (I had a good flush of water there, I would keep the eels/bucket to about 50 or so but you could go higher)
If you buy 2 buckets, keep one solid (no holes), this way you can nest the one with the holes (and eels) inside the the solid one to transport. It surves as a catch basin for the slime (Which is great with italian bread!

)...You could also put a small block of ice in the solid bucket to keep them cool with out havine the eels come in direct contact with an iceblock. (this is the real secret to keeping them alive and happy, de-simed and cool)
So for 10 bucks you have a eel storage system....
good luck.