Creating photo realistic water is different for each image/animation. What works in a day time shot won’t (necessarily) work in a night shot. I too am playing with the ocean modifier looking at the same thing. The scenes I am trying to create are ocean scenes with horizon in which we will be combining with live action footage. The scenes will change from day to dusk to night and morning.
I have found, using BI, which is not the greatest for photo realism, I use a material that is black with almost 100% reflectivity gives me the best results. I create a pure white texture for the foam. And the foam makes a HUGE difference. For lighting I use shadeless HDR images that I manually place around the scene. To light the foam I use a sun lamp tinted to what ever compliments the HDR lighting.
I would love to use cycles, but due to hardware limitations that is not possible right now.