Pokemon platinum question-elite 4?

I think your team seems pretty good. I am not sure of the Pokemon Platinum Elite 4, but I usually try to make my teams very diverse. For example, your Luxray knows 3 electric moves and mine knows 2 (1 being Charge) and a Normal and Dark move. Rhydon is a very good choice, but if you have a friend nearby who is willing to trade you, I would evolve it into a Rhyperior. Overall, I think your team is a good choice.