Well there is loads of info on here that you can print out and to take with you and maybe leave with your GP. I'd use the appointment as an opprtunity to share the highlights of Zamboni's work and see if you can get them to agree to do their own research based on some of the links you've left them with, and then see you again to discuss
I very much doubt that they will have heard of CCSVI. Mine hadn't thats for sure.
I think tests in Poland work out at about 200 Euros plus flights and accomodation, so not that much really.