Luigi said:[stuff]
If you want to maintain the water theme and still have punch power, go Gyarados (Highest water pokemon attack, that isnt legendary) Slowking or Empoleon (Highest water pokemon special attack that isnt legendary, I think, (check me on this)) Swampert/Sharpedo (Second highest attack of a water pokemon that isnt legendary.)
Of course, check me on the stats, I only did a quick run down of the pokemon I thought had the highest offensive stats for water pokemon, I could be wrong. Also, never was a fan of Salamance or Metagross, so cant offer opinion there.
===edit===
I was wrong, Gyarados does not have the highest attack stat of water pokemon. That honor belongs to Kingler (130 according to Serebii). Beating out Gyarados (base of 125.)
===edit===
Once again I was wrong, this time about the higesht special. The highest special belonging to a non-legendary water type pokemon, is Omastar, followed closely by Gorebyss. (115 vs 114.)
With Empoleon and Vaporeon falling behind at (111 vs 110)