Go to http://www.hemopet.org/services.html
There are links there, and also a very good audio file there that has some great history and good explanations.
The full panel is $85 at Hemopet, so your vet should only be charging for the draw and shipping. If they want to send it to Antech, or Idexx, or MSU, you can ask them to ship it to Hemopet, or you can just ask them to draw and spin the blood, and ship the plasma yourself.
Here is the link with Antech's profiles
http://www.antechdiagnostics.com/antech1.shtml?n=ts&p=thyroid%20profiles
you would definitely need the profile 5, but I would personally insist on Hemopet rather than Antech, because I don't see T3 or free T3 on that test, only T4, free T4, Thyroid stimulating hormone, and thyroglobulin autoantibody. Also, Jean Dodd's interpretations take a lot more into account, like breed and diet, which others do not.
I would expect $20-30 for the blood draw alone, and I'm not sure how much for shipping, because it must be shipped overnight, but you should be able to get an idea from your Post Office.
Were you able to find a vet that uses the Idexx Snap 4dx?
-Nicole