How do you get the following pokemon?

Vuplix, I'm pretty sure you can get on Cinnabar Island. Ninetails is the evolved form of Vuplix after you give it a firestone.
Meowth I think is around Mt. Moon or Rock Tunnel. The grassy areas basically. And then I think Meowth will just evolve into Persian or you will need a Moon Stone.
Gengar is the evolved form of Haunter after you Trade Haunter.
Hitmonchan is the other Pokemon from the Fighting Dojo.
Magmar is very rare on Cinnabar island.
Pinsir is in the Safari Zone. If you are strugglin there, just go into the Safari Zone and then just do the "Rare Candy" cheat.
Vaporeon: evolve Eevee with Waterstone.
Jolteon: evolve Eevee with Thunderstone.
Porygon: I think you Trade it with one of the "trainers" of the game.
Omanyte is the Helix Fossil.
Omastar is the evolved form of Omanyte.
Snorlax: one of two places you encounter him.

Its been a long time but
Vulpix-probably blue version or yellow
Ninetails-evolve vulpix
Meowth-probably blue version
Persian-evolve meowth
Gengar-It evolves when you Trade a haunter to another person via link cable
Hitmonchan-you had the choice of Hitmanchan or Hitmanlee in the fightning dojo. If you selecyed Hitmonlee you have to Trade with someone who selected hitmonchan
Magmar-probably blue version or yellow if not in the burned mansion on Cinnabar
Pinsir-I think it bought at the game corner in celadon
Vaporeon-Water stone on evee
Jolteon-thunderstone on evee
Porygon-I think it bought at the game corner in celadon
Omanyte Had a choice between helix (Kaboto)or the other (omantye). Gotaa to Trade with someone who selected omantye
Evolution of Omanyte Train omantye to level ??
Snorlax-Can't you catch it when you battle it after playing the pokeflute Thats how in yellow.

Vulpix - Poke'mon Blue Cinnabar Mansion
Ninetails - Evolve Vulpix with a Fire Stone from Celadon Department Store
Meowth - Poke'mon Blue, In the grassy area right before Vermillion City
Persian - Evolve from Meowth
Gengar - Trade a Haunter at any level.
Hitmonchan - Trade from Blue or Red if you choose Hitmonlee
Magmar - Poke'mon Blue Cinnabar Mansion
Pinsir - Poke'mobn Blue Safari Zone
Vaporeon - Evolve from Eevee with a Water Stone, Trade with another Blue, Red, or Yellow for another Eevee
Jolteon - Evolve from Eevee with a Thunder Stone, Trade with another Blue, Red, or Yellow for another Eevee
Porygon - Buy from the Game Corner for 9,999 game coins (200,000 Zen)
Omanyte - Trade with a Red, Blue or Yellow which choose the Helix Fossil
Omastar - Evolve from Omanyte at level 40
Snorlax - Catch either of the 2 that block your path West of Celadon or East of Vermillion