Hope in good results for you keep us informed about the progress.
I'm not trying being rude believe me don't take it personal
put it this way: you could be in a eastern Europe country, where your salary could barely cover the cost of 2 meetings with a functional/naturopathic doctor(no other money left for your monthly living) where the health system is not even half of the NHS, where no tests like this are available and even CFS/ME is a Science fiction diagnostic and everything including a gut infection "is in your head" and you can't afford neither the simple NHS tests in terms of money.
just be glad you have this chance to be able to pay for and to have a proper doctor for. Really hope you'll find a cure I know how hard is having CFS