You'll find Espurr and Shinx in that area on the routes to and from. Route 36 to the north of Goldenrod or south of that city has Litleo. There's Meowth in Goldenrod itself. Glameow as well, but those can be found on Route's 38 and 39 as well. Purrloin and Skitty can only be caught wild in Kanto. Absol and Zangoose are cat like... but I don't think they are true cat Pokémon. Zangoose is listed as a cat ferret on the Dex, so if that's enough for you, go to the Safari Zone of Kanto for that one.

[Blame Greed as well for getting Lightning into the cat collecting business.]

There's breeders that have these Pokémon as well.