I don't have a lot of information about this, but I will tell you what I know. The best artificial hair is manufactured in Japan by a company called Aderans. The brands are Toupelon and Kanekelon. It's not cheap. Aderans sell their own hair systems retail, but I think a lot of other manufacturers can buy the hair and make the systems to order, so you should just pick a few places and enquire. The advantage of artificial hair is that it never fades or becomes dried out. The disadvantage is that you can't bleach it or dye it, so there is no way of concealing the knots, so you would have to go for an injected base or a style where you have thick density and you don't expose any hairline. I read that Ed Katz, a very expensive Hollywood wigmaker who made William Shatner and Burt Reynold's pieces, uses synthetic hair, but with a thin layer of real hair at the hairline so that the knots can be bleached. So I guess that is possible too.
Good luck with your researches.
Noah