As above - not really such a thing as off the shelf when you are talking aftermarket. The reason you get an aftermarket barrel is exactly the reason that there are no “off the shelf” offerings. If you want a standard .308 20” or 24” bull barrel with a 1/10 twist there are numerous factory offerings of exactly that. Will they shoot as good as a custom - probably not, but they will shoot better than 99% of the shooters out there.
The reason most people get a custom is because they want a 28” .308 barrel with a 1/9.5 twist optimized for 178 gr ELD’s. The next guy wants a 16.5” .308 barrel for a “Shorty” build, with flutes and threaded for a muzzle break, or a 22” ultra-light for a mountain rifle build. There are just so many variations that there would be no way to stock custom barrels.
Most of the major (and even minor) barrel manufacturers offer Savage pre-fits. Jerry can get you Shilen, or MacGowen. There’s Bob Jury, and IBI. Gary Eakin at Bighorn has Benchmark. Etc, etc, etc.
First you need to decide what you want/need as far as specs go. Then it’s just a matter of google-fu to find which barrel maker offers what you are looking for. Find a dealer in Canada, place your order, and......wait.