hey redneck...
i wrote the below before i reread your post and realized you're looking for wheat for your cats but this would apply to cats also.
wheatgrass seed is simply wheat grain which can be found at various ag stores in the area. i can give you directions to an ag store in bacong that has wheat if you can't find it anywhere else.
thing is.... wheat comes in several varieties and it's been a while since i played with this stuff but i believe ''hard red wheat'' is best for wheatgrass. i believe that's also the best wheat for whole wheat bread but i'm not positive. Yan Yan Commercial might have whole wheat grain for bread (called whole wheat berries by some) (225-6814)
you've probably been reading up on it and maybe missed this site. Mercola mentions bitterness but he doesn't say that the bitterness has a lot to do with the growing conditions and... the quality of the soil.
The Potential Health Benefits of Wheatgrass
good luck...
norm : ))~