Growing Herbs in New Greenhouse

I'm buying a home that has a professional (i.e. heaters, fans, plumbing, etc.) greenhouse. Always the opportunist, I thought this might be an excellent catalyst for a business opportunity to grow herbs that might be in high demand at quality restaurants, etc.
What herbs or plants (legal of course!) do you suggest I investigate growing for the health food, restaurant or other type of market segment?
The greenhouse is approximately 20 x 40 and located in Houston.

Sandie Shores will be speaking on this topic at the Richters Third Commercial Herb Growing Conference on October 24, 1998. She will discuss which herbs to grow, how to grow them in greenhouses, the economics, and the potential for the future. If you cannot make it, the transcripts will be available summer or fall 1999.
Gordon Creaser will speak about growing herbs hydroponically in greenhouses for the fresh herb market.
There are many herbs you could grow. Among culinary herbs, basil, rosemary, chives, and tarragon would be top candidates, although tarragon does not do well in high heat. The book, "Profits from Your Backyard Garden" (available from Richters), will give you a good idea of what herbs to concentrate on. Although its focus is "backyard" production, it can help you to decide which herbs to start with because it deals with what the restaurant market wants.