I've got a very similar setup to what you are talking about. I've got an 18 inch 6.5prc bartlein on a T3 action. It's been in and out of several stocks and chassis. HNT26, KRG Bravo, MDT LSS, bell and carlson. I have the same rifle setup in a lesser caliber that sits in a Stockys VG. The 6.5prc currently wears a 3-18x44 Trijicon Tenmile, but has previously worn the 3-9x42 SWFA HD... which is also a good option in the 20oz range (20.2oz on my scale). However, my favorite two scopes in the weight range you have indicated are the 2.5-10 NXS (20.5oz) you mentioned and the Trij Credo 2.5-15x42 (22.9oz). Going "ultralight" I've been impressed with the Trij Accupoint 3-9x40 with the mil-dot reticle for holdovers since it has capped turrets... at only 13oz it feels a lot more robust than the little swfa 2.5-10x32 mentioned earlier. Also a good scope, and I haven't had any issues with mine, but there have been a few reports of lemons.
I'd say if you have the budget, upgrade to a chassis style stock (hnt26, MG element, LSS, etc). You won't have to worry about bedding issues or barrel channel. The factory tikka stock is the worst about being finicky with action screw torque... even in the carbon stocks (although you can get rid of most of the issues switching to a metal bottom metal). But this is a non-issue in a metal chassis. You can also play around with lighter aftermarket stock options to get the weight way down on the chassis, and have the option to run a folding stock... which is way more compact... for example, I've got my hnt26 chassis down to about 21oz after making a simple adapter to run a lighter weight folding stock.
However for your target weight of 9.5lbs (assuming you mean including scope, rings, mag, and suppressor), I'd work backwards to meet your target:
10.4oz (my ultra7 including cb brake)
20.5oz NXS
3oz (DNZ 1 piece rings)
1oz (butler creek scope caps)
4.9oz steel short magnum aics Mag 4 rounds (3 round MDT aics poly style short action mag is only 1.4oz, but currently only fits the non magnum short action cartridges, or 1.5oz for factory tikka mag... which can be jimmy rigged to fit in some mdt chassis options...)
0.3oz for a small 3 spare round ammo sleeve
6.8oz for 7 rounds of loaded 6.5prc ammo (147eldm)
9.2oz (for an ultralight bipod like the Spartan Pro with adapter)
57.6oz total accessories weight (assuming you don't run a sling)
So, 152oz (9.5lbs) minus 53.2oz is 94.4oz. Thus, as long as your finished bare rifle weighs less than 94.4oz (5.9lbs) you will have met the target weight of 9.5lbs "all up". Basically, you then just need to know the weight of your barreled action to figure out how light the stock or chassis needs to be. For reference... a very lightweight kimber 84m barreled action with a 16-18 inch barrel will be in the 44-49oz range. A tikka stainless superlite cut down to 16 or 18 with upgrades like a fluted bolt will be in the 54-57oz range. A Christensen Ridgeline Titanium barreled action in the 55-58oz range. A tikka action with a heavy 18 inch unfluted barrel, but with a fluted bolt would be in the 74oz range. With a heavy, but fluted 18 inch barrel, you'll be in the 68 -70oz range with a fluted bolt and ti bolt knob on a tikka Barreled Action. So, depending on your barrel weight... you could make this work with stocks weighing in between 20-40 oz...