Question about White Ink

For years i've dreamed of getting a huge tattoo, and for years i've had my own design in mind which as of now will be taking up most of my back and reaching out to form two half sleeves. THe only thing is that I don't know Where to go for it since i need White ink to be involved. I refuse to let my own skin color be part of the tattoo. I've heard rumors that you need to go in ALOT to get it re-done, and i heard that not many shops carry the pure white ink that would be needed. This is a very important tattoo to me, so please if anyone has any insight into this, please share. Thank you very much, D. K.