Smaller powder charges and lower pressure at the spout suppress better. Larger calibers lose less velocity when shortened. The cost of threading a barrel is usually a pretty good discount off a .308 that's already threaded. An 18" $400 Ruger American is only $250 if you were going to have to pay $150 to get your /06 threaded.

Performance of different suppressors isn't a lot different, but improvements are being made constantly. The main thing is for a hunting rifle is whether you are concerned with weight. Most people want light, but if you tote it in a sxs and only sit in shooting houses maybe not. When I bought one for deer rifles, Silencerco Harvester Evo was a great choice and I've been pleased with it. Since I bought it a local manufacturer came out with an equivalent can, so I would have got that instead. The one I'm thinking about buying now is a different design that came out since I bought the Evo. See where I'm going with this? It's hard to recommend something when the state of the art is constantly advancing.

Then again, a pair of electronic ear muffs or plugs are pretty cheap. Bluetooth is pretty sweet.