Major lavender farms are usually in the business of producing the essential oils of the plant. but the beekeepers in those areas may produce single-variety honey.
I know of big lavender producers near Mona, UT, Sequim, WA, and Yamhill, OR. I'm sure there are big lavender farms in the Midwest and east, too, but I'm not familiar with them.
Not the specific information you are wanting, I know, but a point to begin looking.