Dr. Brownstein is on record recommending 200mg daily for Iodine deficiency disease, such as fibroids and 300mg daily for cancers.
So your target dosage is very close to what Brownstein discusses. I always try to form my opinions on what the Iodine doctors say. So I have extensive files on the Iodine doctors located here to back up anything I might say:
http://tinyurl.com/Iodine-Reading