High end optics can range from under 20oz to over 40oz. It really just depends on what your needs are. If you want something that tracks reliably for longer shots it’s going to weigh more, if you can keep that under 30oz you’re doing pretty good.
The Swarovski scopes with the BRH reticle are awesome if you’re trying to keep things light. It’s a very simple mil based tree reticle and on a 6.8 Western should get you out beyond 700 yards with holds and the Z3 3-10 version weighs a hair over 12oz.
Keep balance in mind though, the only think worse than a heavier rifle for hunting is an unbalanced rifle. If you’re going to have a suppressor off the end you’ll likely need more weight in the optic for good balance.