I dont know if you are accurate in your information... I myself am part of a co-op here just south of seattle.
A co-op is different than a dispensiary.
A co-op is an individual or group that pools their medical grow 'permits' so they can grow larger amounts in fewer areas. (also to supplement because some people can't/don't grow their own) If you belong to a co-op, i believe you can not grow your own (someone else is growing for you.... unless your the lucky one with XX amount of plants)
If you are looking to start a dispensiary as i think is your question, i know of no one in washington that can help. Our laws still say selling cannabis is illegal, even to patients. Its all in the wording.
If you have any luck in your search for 'B' let me know, as i have also been contemplating an adventure such as this. Until then, maybe you can look a little harder for a co-op... again, I know of at least 3 in or around Seattle