scopes
You are on the right track with a scope that has a smaller bell, ie, less than 40mm. A tidy, light rifle, with a big scope on it not only looks out of balance to me, but is heavier than it needs to be, as you have determined for yourself. I would stick with a 1" tube, as a 30mm tube usually adds weight as well. A decent 1" tube/glass will give you plenty of light to shoot by during legal shooting hours.
I am a bit of a dinosaur regards fixed power scopes myself, and in the early years, all said that "4X was all you needed" and many fellows of my acquaintance even ran 2.75x and 4x scopes with no issues. Fixed power scopes likely were a bit more reliable than variables years ago. I still run several fixed power scopes but have moved up from lower 2.75 and 4x scopes to 6x36mm Leupolds on deer rifles. I have not found 6X a hindrance in the woods, and for the life of me cannot understand the "all I could see was fur" comments you read and hear, some even on this thread. I've found 6X allows for point counting on property requiring certain point counts before shooting, which is really common in my area, both on public and private land. We did not have to deal with that years ago. I also believe 6X allows me to pick windows and lanes through the woods for a clear shot, which I could not see with lower magnification. The added magnification over 4X seems to aid shooting groups and zeroing as well. I do not have numbers in front of me, but suspect a fixed 6x36mm is more than a few ounces lighter than a 3x9x40, as they are a trimmer and have fewer lenses than say a a 3x9x40 variable, and possibly even a 2x7 or 2x8 number However.....
Good modern variables are now far better optical devices than they were when I first started hunting, some 50 yrs ago and I now have nothing against them provided they do not get to big. Stay with a good name brand and you cannot go too far wrong. I am a Leupold man myself, but own a few Burris's as well. I think Nikon makes a good product, but only have one example. My experience with Bushnell, Tasco and Simmons have not been positive over time. Vortex is receiving a lot of press, as is the "new" Redfield as owned by Leupold, but I do not have examples of any, nor can I advise on Sightron or any of the $$$$$ Euro imports.
To finish, I have a Leupold 2x7x33 Vari-X-II a (I think) which has been on at least 3 rifles and in recent years has been hunted hard on my only stainless/synthetic rifle that I use in wet weather and to climb trees with a climbing stand. It has been as reliable as a rock, and I suspect it's new brethren or cousins would be a fine choice for your new rig.