Yes, the Titanium-dioxide is the main part of the white pigments. (You can add some Magnesium-dioxide, too, but not essential).
I think Titanium-dioxide is available in any chemicals's store, in the States, like everywhere. It is very cheap.
But...
It is not enough to simply mix it into any lacquer-type base (like dope, etc.), even for hours, since Titanium-dioxide likes to remain together, making smaller-bigger granules.
First step must be to make a paste with relative few dope, by rubbing. You can it make easily, at low rpm, with a soft plastic "tongue" assembled onto mixer's "T" element. Be sure, this tongue can touch the bottom of the mixing can. When you feel the paste as smooth like cream, or thick honey, you can add more dope (or other lacquer), step-by step, drop-by drop.
Istvan