These are all latex free. I myself would choose one of these, of which are all latex free and rate a 10 on the safety scale. As far as which one would be best, it would all depend on your preferred length, thickness, and features.
Me personally with my preferences, would love this one due to the look, material, size, and features. I don't use harnesses, but I love suction cups.
Fortunately there are plenty of latex-free materials -- silicone, glass, wood, stainless steel . . . if you look on the left hand side of the page when shopping, you'll see there's a list of features for sorting purposes. Just check "latex free" and you're good to go.