Since the need is two or three of them and that rules out most out-of-production pistols, Ruger Mark IV is the "easy button" answer with Standard, Mark II, and Mark III also being good choices.
My workhouse rimfire is a Ruger Standard RST-6 that was made in 1964. The original finish was worn to the metal from handling, and it was Cerakoted back in 2017. This pistol still sees about fifty rounds per week and has been totally reliable with a wide variety of ammo from 36-grain high-velocity HP to 40-grain standard velocity offerings. The only functional change I made was to add a Volquartsen extended magazine release to allow easier removal of the newer ten-round magazines.
The good news is shooter-grade samples are available as people trade them for the easier to field strip and assemble Mark IV pistols. The benefit of the Mark IV is that Volquartsen sells discarded uppers (they use the lowers for their custom offerings) dirt cheap on the clearance page of the website. For example, pencil uppers for $35 delivered to FFL and Lite uppers with sights and the optics rail in the box for $110 delivered to FFL. Bolts and other spare parts are often available on Volquartsen's eBay store at https://www.ebay.com/sch/volquartsen...1&_ipg=&_from=
Hard to go wrong with the Ruger Standard/Mark pistols.