I just got a Yaufey 30-pt off of Amazon. It's cheap, quiet, energy efficient, and it has a hose for continuous draining if changing the res becomes too tedious.
Big thing to remember is the room outside of your room. If you have a 4x4 tent, like me, its tempting to get a small dehumidifier to accommodate the small space and help your wallet. The problem is that my tent has a fan and draws air in from the vents, so I needed to get a humidifier big enough to accommodate the room outside of the tent. Good luck! Hope this helps!