CCI standard velocity is extremely accurate in several of my target guns, should make an excellent suppressed round. It is not the slowest / quietest ammo out there but it is close to 100% reliable in all my semiautos, haven't had a dud round in 1000s of shots, and sub MOA accurate at 50+ yards.
Some of the 'quietest' rounds wont cycle your semiauto BTW.
What firearm will it be mounted on? Pistol or rifle? Semi-auto or bolt/lever/pump/single shot?
Most semi-auto rifles will not reliably cycle subs without special tuning.
Most handguns will keep all .22 ammo sub-sonic by the time it leaves the barrel
The quietest ammo I've fired out of my Savage MkII suppressed has been CCI quiet, hands down. But it's also not very effective on live targets. I've had to shoot rabbits multiple times in the head before they stopped flopping.
CCI Segmented Subsonic is almost as quiet (still quieter than a BB gun!), but anchors your target on the first shot. I love the stuff.
CCI Suppressor (Sportsman Guide) is another option that I like because of the 45 gr bullet. It works flawlessly in my semi auto pistol and rifles and, at 970 fps and 94 ft-lb, it is even quieter than standard. I haven't tried the 29 gr CB-longs at 710 fps but the Quiet at 710gr and 40gr don't work my slides. They are noticeably quieter.
Trajectories are noticeably different.
Willie, what type of gun(s) will you be shooting them from?
With a pistol length barrel of 5" or less, I find that EVERYTHING that's marked "standard velocity" is actually subsonic.
But from an 18" or 22" barreled rifle, about 10% of some specific brands and styles of "standard velocity" ammo goes supersonic.
I always find CCI Standard Velocity is subsonic in everything.
So is Federal Gold Medal match ammo.
So is Eley Tenex, and Wolf Match Target. That's pretty expensive ammo, though.
I'd find whatever "standard velocity" ammo you can get a good deal on, and buy a case of it. If it stays subsonic in your gun, great. If not, save it for when you'll be shooting it without the can, where noise doesn't matter. You still got a good deal on the case of ammo anyway!