Go with a surf rod. 9'-12'. 4000-6000 size spinning. with 30# braid.
I second this advice although we fish with 17# Andes mono and have hauled in tons of big stripers below Denison Dam.
Edited to add: Below Denison Dam when they are generating is still one of the best places to striper fish. In fact, several members here met with my son for a mini-tournament the Friday after Thanksgiving several years ago. We all had a lot of fun even though the really big fish did not show up that particular day.
On the Texas side when they are generating, you will need to cast beyond the swift water into the pocket they call the shoe. Otherwise, cast up into the "hole" which is where the water comes out through the generators. Many times you can actually see big fish resting there out of the current in the show. On the Oklahoma side when they are generating cast to the seam where the swift water ends and you are out of the current. Hang on to your rod because many times fish will hit it as it will never hit the bottom.