Live food is likely to be a disappointment. Smaller fish will disappear during the night, but I suspect the eel comes across them while sleeping on the bottom. I've seen no evidence of very active hunting of a swimming fish. Worms or any kind of meat is a fine choice (commercially available beefheart or other frozen aquarium foods, shrimp, liver or whatever), and they will learn to take sinking pellets after a while. They're normally nocturnal but can be trained to daytime activity by feeding with room lights on and/or shortly before lights come on.
You should supply a thick layer of sand in the tank to make this fish comfortable. I'd recommend 2-3" depth for an eel that big. They like to burrow but will come out quickly when they smell food. Also keep the tank very tighly covered. I've lost several of these from tanks where I really didn't think they could fit through the covers, and one had even been kept in an uncovered tank with no problems for months before escaping from a well-covered one. I've never found it, it just disappeared.
Hmm good point...but that nightcrawler did appear to die after being chomped on, but none of it was eaten. And what about a weak fish?
I've also been considering putting him in a brackish tank. Right now he's being kept in freshwater in an opaque rubbermaid(i thought the opacity would help keep him comfy until Saturday when i can move him). I'm not gonna do anything for another day or two, these past few days must've been incredibly stressful for him.