Pokemon FR Help

So, i just picked up Fire Red again, and i've run into a little bit of trouble.
I just got my eevee in celadon city (and a female one at that), but i'm stumped if i should evolve it into a flareon,jolteon,or vaporeon, and which one of the 3 would benefit my team the most if one of my pokemon of the same element go down.Here's what i have on my team:
Growlithe
Nidoking
Pikachu
Gloom
WartortleThank's for your help.

jolteon in my opinion since your water-type is wartortle and your fire-type is growlithe , i see that pikachu being weaker than either of those two and its more likely to go down in a fight first.. also jolteon gets pin missile which will help you against the 7th gym leader (uses psychic types if i remember right)