Grass: Exeggutor or Victreebel are the best in my opinion.
Fire: Vulpix is found in your version as is Magmar. I personally like Magmar because it can learn Psychic.
Last one: Psychics are unfairly powerful in this game. Alakazam and Hypno are popular picks, though Jynx can be good too and has the Ice type for killing Dragonites. Ground types are also useful though that'd give the team a 3X ice weakness. The best Ground types are Golem, Rhydon, Sandslash, and Dugtrio (who isn't that strong physically but is incredibly fast). As for moves (warning, I suck at old versions);
Blastoise: Surf, Blizzard, Double Team, Rest
-some people like Earthquake though I don't feel Blastoise has enough power for that. It is very defensive overall. It may do well with EQ and Body Slam in place of double team/rest.
Pidgeot: Wing Attack/Fly, Mirror Move, Toxic, Double Team
-meant to be evasive and annoying. This bird has few options. Mirror Move may not be needed and maybe could have Rest in its place for the evade/heal combo.
Jolteon: Thunderbolt, Thunderwave, Reflect, Substitute
-man, Pokemon sure were limited in the old days. Reflect helps out its poor defense and sub increases the annoying-ness. Electric moves are obvious.
Exeggutor: Stun Spore/Sleep Powder, Psychic, Leech Seed/Mega Drain, Explosion
OR
Victreebel: Sleep Powder/Stun Spore, Razor Leaf, Swords Dance, Acid
I am pretty sure neither of them learn Body Slam. Exeggutor has great defense, attack and special stat making it very hardy and strong. Victreebel has great attack stats and decent speed but lower defense and HP. Both of them lost their special defense in the newer games as a little added note.
Ninetales: flamethrower/fire blast, fire spin, toxic, confuse ray
OR
Magmar: fire blast/fire punch, psychic, body slam, confuse ray
Ah, good old stalling and annoying Ninetales. Some people like body slam on it though the attack stat isn't too high. Being fast helps make fire spin more effective and, if it doesn't miss, is a great way to slowly faint an opponent. Magmar (I think) has a bit lower special and average speed but good attack. Though Magmar can learn Flamethrower in GS, I don't think it's a good idea to backtrade moves a Pokemon couldn't learn normally in the old games.
Alakazam: Psychic, Reflect/Seismic Toss, Thunderwave, Recover
OR
Hypno: Psychic, Seismic Toss, Double Team, Rest
OR
Jynx: Lovely Kiss, Psychic, Ice Beam, Bubblebeam/Reflect
I'm not good with either of the first two guys. Alakazam is very fast with a high special, but Hypno has much better staying power. I am unsure if the yellow tapir can also learn thunderwave. Jynx is great because of Ice Beam and Lovely Kiss. Reflect helps out her poor defense. Her special stat back then was fairly average as is her speed, but not low.
