For keyboards I’d highly recommend Filco, Daskey, and Ducky. The former 2 are more ‘no frills, all business’, the latter has some RGB offerings, but most of the keyboards those guys make are plate-mounted mechanical, plug and play, with really decent build quality.

I don’t know shit about trackballs but my Dad forgot his when he came up to visit (Minnesota-Arizona snowbirds) so I bought him an ELECOM DEFT PRO from Amazon and he loved it so much he started using it over the one he forgot to bring. Might be worth a look - also a plug and play type device