I sell suppressors now only through Silencershop but I used to do them directly. I have tried many different brands and types on different platforms. I am also an advocate of buying one suppressor to do many things as money does not grow on trees. One of my favorites is the Liberty Mystic (9mm/.30) and its big brother the Cosmic (.45). They work great on everything including pistols. It can easily be cleaned so you don't need to worry about shooting dirty .22LR or hand loaded lead ammo. They run about $600 not including the adapters. On a .22LR or PCC you can use the provided aluminum adapter that comes in 1/2 - 28 or 5/8-24. For any rifle caliber you will need the fixed rifle adapter which runs about $80. To run it on semi-auto pistols you need the piston booster with the correct thread pattern which runs $130. So for about $1000 including the stamp you get a can to do it all.
As for sound there is not much difference in total DB shooting a .22 bullet through a .30 or .45 can. There is a difference in tone, but not volume. Of course all supersonic ammo will have the crack made by the bullet breaking the sound barrier. .22LR subs will be super quite as will .300blk subs and 147g 9mm.
Another viable option is the Thunderbeast 5.56 takedown. I run this on my F/A M-4 due to the volume I run through it. It is a sturdy can that can take a beating but comes apart to be cleaned easily. It also works great for 22LR. I have run it on my Ruger 10/22 and although heavy it is extremely quiet with 22 subs. I also run it on my long range .224 Valkyrie which is also very quite.
I have sold a few of the Optimus cans and my customers like them. The ability to shorten or lengthen the can does have merit but it is an expensive can. IMHO the Liberty Mystic is a more viable option.