Hello! (You should post an introduction before the site-police nab you.
)
You are asking a few different questions.
For calibre choice: What kind of shooting are you doing? What distances? Is it important that your shots are near silent?
For choice of brand and model, CZ have a lot of fans. They are a rock solid, reliable, agricultural item which most owners do some kind of trigger modification to. A Sako Finnfire or Anschutz 1417 (for .22) or an Anschutz 1517 in .17hmr second-hand would be my preference over a CZ new. The Weihrauch HW60 and HW66 models are well respected as are the Sako Quad.
There are quite a few good moderators out there for rimfire. If you are buying second-hand, then your choice might be determined by what comes with the rifle. Scope choice, again, will be dictated by intended use and budget.
So..... what are you actually planning to do with the gun?
regards
Ian