Dont't rely on your hygrometer unless it's NIST certified. Something like an Extech. TEC fridges are great, but depending on your local weather, it might take a little more than just beads to balance out the swings. Something like a brewery thermostat thingy sometimes becomes necessary, but they're only like $80, and I think you only really need them in the desert. Beads are fucking great, but it's way cheaper to buy kitty litter.
Dan's right on the sizing comments. When it comes to humidors, always buy something you think is way too fucking big.