Unfortunately you can't measure egg quality at all, you can only get an idea of egg reserves through things like amh and antral follicle scan. When I say my egg quality is poor, I'm just assuming that's the case based on my age, 4 miscarriages and failed IVF. FSH does vary from month to month, I don't know why but I know that it does which is why it's advisable to get more than one test, your follicle count will also vary slightly from month to month. 6.5 is a really good result, 13.9 not so great but not terrible and probably about right for your age.
The supplements you've listed are all good, just be aware that for women over 40, ubiquinol is thought to be more effective than coq10, it's the same thing but in a different format. Take the coq10 that you've ordered, it certainly can't do any harm, but when it runs out maybe consider moving to ubiquinol - it's more expensive you you won't need such a high dose. Is it vitamin D3 you've ordered? Stop taking evening primrose oil at ovulation as it can cause slight uterine contractions and so isn't advised for the second half of your cycle when ttc. You probably know all this vitamin information already so huge apologies if that's the case.
I find the fertility friends website to be a fantastic source of information, they have boards for different regions around the world and for each region, threads on different clinics. The women on there are all long term ttc-ers and a fantastic source of information, it's worth spending some time browsing through there to get an idea of clinics. The most popular ones seem to be in Greece, Spain, Cyprus and the Czech Republic. Most clinics will do a skype consultation free of charge so you can get a feel for the clinic without having to travel. Some clinics also work with a coordinator base in the UK who can help you navigate the system although to be honest, I've found dealing with my clinic in Athens to be extremely straight forward. You would then need to be out in whichever country you choose for a period of around 10 days although I have seen some women travel back and forth (more difficult with Greece but fine for Spain and Prague). Also you can have scans and blood tests done in the UK rather than spend the whole 10 days abroad.
Best of luck.