Aguila may have something for you
to consider, it's called "Colibri". I believe it comes in two flavors, one for sure uses a 20 gr pill, uses priming compound for around 325 fps if I remember correctly. I think they have one either more or less powerful, the hot shot being the Super Colibri. As far as accuracy, I have no experience nor have I read anything on them - accuracy report.
If you google up Aguila, you can probably fill in the blanks.
JUst to get everyone on the same page, if it is in the CB cap family, I feel sure it will be subsonic. Whereas a lot of mfrs produce subsonic ammo which is still around 1100fps............OK, just crunched 740mph which I think is sos at sea level, but close enough if not, and that is 1085fps. A lot of std vel 22 ammo is at or under this, some are labeled sub sonic.
What sub sonic means is the projectile is not breaking the sound barrier, giving the "crack" to the report. You will still have noise that would require a suppressor to dissapate. This may be going in a different direction than what you intended so toss out what you don't need.
