I did 45% r\h, wouldn't go too much lower than that though because the d\h will suck the water out of the plants too quickly, and lessen your flavor\taste though I suspect 40% would be fine. You want a slow dry if possible though. Hang the entire plant by it's base, they fit very nicely actually. Chopping each individual branch and hanging them seperately will also speed up your dry.

As for curing, yeah you need something air tight. I have seen people use turkey bags - though they aren't 100% air tight, they do hold alot of the gases inside and also prevents your whole house from smelling like herb. Me personally I use big mouth jars, I just load em up about 1\5 from the top of the jar, pack the nuggets loosely... they want to breathe and open the jars up every so often. Good luck.