Rock River is decent.
I would pass on that Daniel Defense mount if I were you. Aside from the fact that you don't have a T-1 or H-1, The DD mount is $71 and a LaRue QD mount is $107. An ADM QD mount is $92. I would much rather have a QD mount than a permanent mount option. For an extra $21-$35, you can get a superior mounting option when you get your optic.