I don't know if this one has a low pH, but I remember the L'Anza Moisturizing Conditoiner & Detangler combo providing me with some really good elasticity. I ended up taking them back because I'm a PJ & I knew I'd be switching products in 2 weeks again anyway
You can use Roux Porosity Control shampoo and conditioner. It improves the elasticity and porosity of the hair. And you can purchase the sample bottles also.