Kanto-derived perfect Pokemon team?

Hi guys! I really like the first 150 Pokemon and I want to build a balanced team of Kanto pokemon (including their evolutions introduced in subsequent generations e.g. Electivire or Rhyperior). I would really like to have Charizard, Venusaur and Blastoise on my team. Im thinking about including Electivire and Rhyperior and I need your advice on that as well on the 6th Pokemon. Maybe Gengar? Any input will be much appreciated. Thanks