Scott,I would start the brace height at around 7 3/4".Shoot it and try increasing and decreasing till you find the quietist position.It is a good idea to do this before installing silencers.
You could start your nocking point at 3/4" above level with your arrow nock under the nocking point.Experiment with the height till you see no up and down wobble of your arrows in flight(porpoising).After finding the best location,I always add a second nocking point below the arrow nock.It insures that the arrow nock doesn't ever slip down.