Your team should be at level 40-50. A good team with Typhlosion would be:
Umbreon: Deals with Will.
Dewgong: With Hydration, RainDance, and Rest, Dewgong will be hard to take down. It won't be injured by status, and it is good to take down Lance with.
Gengar: A Pokemon that is useful in dealing with both Koga and Bruno. It also can beat Will if they don't hit Gengar.
Heracross: Heracross is a useful Pokemon against both Will and Karen.
Dragonair/Dragonite: Backs-up Dewgong against Lance.