Starmie is a must have, for BoltBeam. I think you can have that in Red anyway. Lapras is a good tank. Poliwrath for some physical power, along with Gyarados. Then yeah Omastar or Kabutops. When I do monotypes (or even monocolor, cause most Pokemon of a certain type also are a certain color), I try to pick a lot of dual types so that I don't have too many weak points. :) And have diverse movesets, though I do all the time lol.