Lula seeds will work well for rootstock.
Agreed. I get avocados shipped from FL not only for the fruit but also to use seeds for rootstocks.
Simmonds = vigorous, big seed. Very good. But shows a little salt sensitivity (not much). Little suckering but not much
Waldin = vigrous, big seed. However tends to sucker a lot, like Adam says.
Lula = vigorous, big seed. Excellent grow, very little salt sensitivity, little suckering.
Like Rob and Carlos say, I like Lula too.