I just purchased a CZ455 .22LR & now need to purchase a nice scope & set of rings for it. Rifle will be used for target practice, plinking, & squirrel hunting. Budget for scope & rings is $350. Any suggestions for either?

I really like the Weaver Classic rimfire 3x9 with AO as an "all around" 22 scope. They usually run somewhere around $250.

Good choice on the CZ. The ones I have shot are pretty darn accurate with standard velocity ammo.

weaver V classic 4x16, the fine reticule with 1/4 Moa dot is awesome for target or squirrel hunting in good light.
RR

Just got a Bushnell Engage 4-16x44mm with the moa based graduated reticle, it's going on my Savage Mark II for range work, maybe try out a few of these NRL22 matches near me.

Well IMO, and I know you get what you pay for, but $350 for a rimfire scope and rings is really high. That being said, you can get one of Cablea's rimfire scopes for a lot less and they are plenty clear and you can use the extra cash to stock up on 22 LR ammo once you find the type your CZ likes. I believe these scopes are either made by Tasco or Bushnell for them but I've been known to be wrong before. They make a straight 4X and a 3-9X. Nikon also makes a fine scope that Cabelas sells for $179.