I am in Sydney, Theresa Vernon has no problems sending supplements to Australia so that is a non issue if going with a US practitioner.
If your potassium is higher than the sodium on the arl chart that indicates potassium loss. There is a paragraph in your report under the na/k section that talks about this. That will be why the lab has recommended sbf for you.
I have no thyroid issues that have been picked up by a doctor, none of the glandulars in sbf have had a bad effect on me.