In general, you will want a longer and skinny kayak, without a lot of rocker. I would be looking at least 17 feet, and maybe even 18 or 19 feet. Probably no more than 22" wide. Probably better for a kayak with a rudder, which lets you focus on going straight fast and the rudder can make the minor adjustments for wind cocking and such.
With your price range, used would be your best option. Current Designs Extreme mentioned above (also goes under the name Nomad) could be one to watch for, and is known as friendly to larger paddlers (Matt Krizan, at 6’7", used one for his paddle along the complete California coastline).
The mention above of asking what race rules you would follow does matter. For example, Cal100 race had a kayak class and a surfski class. Kayak class was 18’ max. (http://www.riversforchange.org/california-100/registration/). Anything above that was racing against surf skis. The CD Extreme is above.
You skill also matters. Generally the faster the boat, the more skill you need to make it work.