You would use the RED belt routing in the very first pic (a couple down from original post)
As for belt lenght....FAR too many variations in what pulleys everyone is using. Stock, aftermarket, mixed and matched alternators, etc.
Best way to find a belt lenght is to get a peice of string, wrap it around the pullies in the appropriate pattern and measure it. I'd buy a few belt sizes and go from there. Settle on one on the "tight" side of the tensioner range as the belt will stretch slightly.