Smith 41 is what I'd like to have and you can get 'em threaded. That'd be the best you could get in more ways than one. They still hand make those in limited numbers and they're tack drivers. They're already over $1000 (about like a Volquartsen really) but I've seen 'em in velvet lined oak cases with the pistol and a separate threaded upper and a can. Really cool. One day maybe... I'd bet the custom shop could make a threaded one, worth a call. It'll be more than $1000 but buy once, cry once really applies here,, and you'd have a no-shit competition grade .22 you could suppress. Yeah, I want one. Here's a bunch, apparently you can get 'em with rails on top now:
https://www.google.com/search?q=sup...rfXeAhVEFzQIHUHSAkwQ_AUIDygC&biw=1280&bih=569
But I have a PPK/S I bought the day I picked up my .22 can. Didn't have a pistol. Wasn't able to find the Beretta I wanted, figured I'd get it later, got the PPK/S and never went back for the Beretta. It's a fairly accurate little .22! No real complaints for what it is. And it's fun and you feel like James Bond. Sorta. I could have gotten the more modern looking one but this one was smaller and more fun.
The Ruger Mk2 is the old standby. I understand the Mk2's are better for suppressing than the others. I've had it explained to me before but it's been so long ago I forget. I don't own one so can't say from experience. But if I were to go that route, I'd get a Volquartsen, etc., pistol or lower, and maybe a Paclite upper. The Kidd integral 10/22 I built is so completely different from a Ruger it's not even a comparison.
Others swear by Buckmarks and such, and they likely are better than Rugers, but a custom Ruger with no Ruger parts is totally different story.
Dedicated 1911 .22's are also REALLY nice for suppressor hosts. They come in all flavors, but good ones can be had for $600 I think. That's another I wouldn't mind having and I'm not a 1911 guy, don't even have one. Now the Glock .22 conversions I wouldn't be too excited about (despite owning nothing but Glocks). Go figure.
For true suppression, integral rifles is where it's at. I got a 10/22 integrally suppressed and it's in a league of it's own. A CZ455 would be AMAZING. Integral pistols aren't much better, and in some cases less quiet than thread on cans. Liberty is who I use for .22 cans, their monocore design tends to work amazingly well in more than a few areas, especially the Regulator. All that said, I still think Elite Iron makes the best looking and a great performing integral Mk2.