4th Gen What Pokemon should I add to my team? Heartgold

I just beat the last gym leader but only have 5 Pokemon what do I need? Need a quality 6th Pokemon to beat elite 4.
My pokemon:
Gyarados lvl 41
Pidgeot lvl 40
Pupitar lvl 40
Typhlosion lvl 40
Ampharos lvl 41

It depends on how much training you want to do. If you don't want to do much training then your best bet is to catch a Pokemon on Route 26 or on Victory Road. If you were playing SS I would suggest Ursaring, too bad you're not =P lol. Anyways, Sandlash, Dodrio or Quagsire might be your best bets if you want a decent Pokemon. Dodrio offers speed, but that would make 3 flying types on your team. You can afford Quagsire b/c Gyra is part flying, and it's a Pokemon I've always loved using myself. Sandslash is aight, Slash is always a good move to have. In the end it's up to you though. Hope I was of some help!

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