Castle Creations Mamba Max if you want to be able to throw serious voltage to it. If not as Tom mentioned the Novak is good stuff. SNG was talking about the Traxxas VXL....think waterproof=more fun and running options. Oh yeah!
You can't go overkill when it comes to esc's. Pick something up that can handle considerably more current than you are going to put in/draw out. Such as the Mamba Max. Isn't the max rated at 3s?