I've worked with Giant Wood Rails and also keep coots (another type of rail)
They are fairly easy to care for, but don't keep them with any small ground dwelling birds. They might make a meal out of them.
A good base diet is waterfowl pellets, along with fish and shrimp. Crickets and meal/super worms are also taken with gusto. Small pinkie mice and meat gel/predator diet can be of use as well.
These guys are cryptic and agile, but they can tame down. I recommend lots of cover in the enclosure. Not really big swimmers but give them enough water to get into and bathe.