For a sight, I like the TruGlo Extreme 5 pin sight. The optic fibers in this sight remain bright even after legal shooting hours. But they are small enough for pin point aiming out to 70 yds. Out of my Martin Onza 3 my first pin is set at 30 yds. Then 40 - 70 in 10 yd increments. My 30 yd pin is 2" high at 20 yds so I know to aim a bit low. I too hunt out of a treestand and for me this sight is perfect for that and also should I encounter a longer than normal shot.
As for the rest I like the NAP Apache drop away rest. Trophy Ridge makes a similar rest. And for the $60 price tag on the Apache, it won't break you. This rest sets up easily and is built like a tank. Its fast and quiet. And you will shoot you best with a drop away.