I think getting on 'em close to the roost is a really great way to pull off a successful hunt. I would get a decoy out if possible, be there plenty early, like in pitch black dark so you won't be seen setting it out. I've been having great luck with full strut gobbler decoys, along with the standard hen.
I normally do several yelps and purrs, trying to get a response from a roosted gobbler. Whether he answers or not, I'd only call a few times, and if other hens are calling, try to imitate them. I've had that work especially when a bird has hens, you can call the hens to you and Mr. boss gobbler will usually follow. I agree with others saying to use a hat or something to make a fly down noise, if there's no risk of being seen. Making some scratching noises in the leaves helps a lot with the realism also.
At any rate, sounds like you're set up for success, good luck!
Zane