This makes them very hard to get so it will take you while.
Also its hard to get Pokemon to appear at all becuase of the spaces in the grass.
There is some one that will give you eevee in castilia city namly amnitina.
But that is after the elite four.
But you can get it just go to the last street on the left I think go in to the building with a big sign and on the top floor amnintinia will give you eevee.
Hope this helps.
Please evolve it into espeon trust me espeom (ruby is the name) is completyly awesome!