I'm not sure on the weight, as I have never weighed them. But I'm sure you could put down a rough estimate using the website data for the rifle and scope. Add a couple ounces for the rings, and you should be close.
As for the Hydro-S vs. Hydro-L, there is a big difference in them. One is a 7" can with 9 baffles, and the other is a 9" can with 13 baffles. There's going to be a noticeable difference in them. I will try to get a video up sooner or later with the Hydro-S vs. Hydro-L on the 6mm ARC. There are also several S vs. L videos on my youtube channel. Just go there and look around and you'll find plenty to watch. Feel free to subscribe, like the videos, and share them with other folks, too.
If you have any other questions, feel free to ask. I'm always glad to help.