Since my last post on this thread (over a year ago), I've actually gotten one
I bought one last spring named Kermit and he's being doing well. I have him in a large plastic Critter Keeper-type tank that's halfway filled with water (which I add marine salt to since they're brackish). I have some rock formations that stick out of the water and give him a couple islands to hang out on.
I don't personally use a filter in my set-up but I'm keeping the tank bare-bottom so I can keep it clean (so no gravel or anything if you do that, as it'd be a pain). He's actually pretty messy so I make sure to change the water at least once a week. I'd like to move him to a larger, filtered tank eventually and get a couple more. But he seems to be doing fine in the current tank for now
I feed him gut-loaded crickets as his staple diet but he'll also eat various frozen foods like krill and bloodworms as well as other feeder insects (he likes small waxworms but that's a rare treat for him). Some will apparently eat pellets but I think it'd be best to offer a variety of foods anyways. Besides, hunting provides stimulation and is cool to watch
Here's a picture of him, by the way:
Overall I think the most important things are to remember to make the water brackish (remember that you need MARINE salt, not freshwater aquarium salt), keep the tank clean, and feed a good diet