Please rate my pokemon soulsilver team for online battling?

Nice, didn't you already ask this? I remember answering a similar question.. Anyways, your team is really good and I would keep Slaking. Giga Impact really creates a good Stab but he doesn't really needs to recharge due to his ability (or vice versa?). If I were you I would switch out Rampardos. He is an awesome attacker, but lots of Competitive Players have at least a dragon type most of the time. I would suggest a Dragonite or Garchomp. Both of these are awesome attackers except Dragonite is more "tank like".