I am a relatively old hand at the forum but know nothing about suppressors. I think I'd like to have a little fun with a suppressed 22.
I don't know what 22 pistols have threaded bbls available or what suppressor to use.I have a Ruger Mark 111 and a Browning Buckmark. I am not interested in a Mosquito (having had one).
Help me get started please.

I'd go with the buckmark. Tactical Solutions makes barrels for both. The barrels are easier to change with the Buckmark and you dont have to order one through an FFL dealer like you do with the Ruger since its not part of the receiver. The browning barrels are a LOT cheaper too.

http://www.mizzoumuleguns.com/id15.html

The Walther P22 has a threaded adapter.

Both the Ruger MK II/III and the buckmark have threaded barrel options from Tactical Solutions.

The Buckmark and Ruger barrels can be threaded by a good gunsmith. I prefer Tornado Technologies for my threading.

There are other pistols and conversions that can have their barrel threaded or an extension added which can be threaded.

An overwhelming majority of 22 rimfire suppressors are threaded 1/2 X 28.

If you have a Buckmark I would recommend that you start there by buying a barrel or threading yours. It is a great suppressed platform and the barrels are super easy to swap.