Hi Joanny,
I can completely understand that you're making a big decision and doing a lot of research into the options available.
My recommendation is not to focus on the material being used, but more on choosing an experienced dentist who uses high magnification, and can plan your new veneers using photography and (even better) a computer simulation as a blueprint. They should be able to give you 'provisional' veneers which means you can test-drive the shape and of the new ceramic ones before you commit to the manufacture of the veneers by hand.
Bear in mind that if you want the most natural look, the laboratory technician your dentist chooses to work with matters just as much if not more! Feldspathic porcelain is layered by hand and the technician can create natural characterisation, but they aren't as durable in some circumstances. e.Max is very commonly used and is more durable, but can sometimes look more opaque. Then again, I've seen wizardry with e.Max from some ceramists!
Cerec, Vita Suprinity and Celtra aren't suitable if you want the most durable and most natural.
Ultimately, excellent dentistry is never a quick fix, but it will be worth it. Like most things in life, you'll get what you pay for. Best wishes!