Choosing between the two, definitely Ankor's shaders. The other is just some post processing of the existing shaders to change the look, Ankor's actually adds new features like reflective water, self-shadowing models and scenery and working reflector gunsights.
Edit: it may be possible to use both at once. I know some have used Ankor's shaders and sweetFX which is similar to ENB. Personally I only have Ankor's installed.