I'd say a 26 lber is very uncommon in the Catawba chain but they are there. If you are looking for quantity, then Norman is the best of those mentioned. The stripers were starting to school in the creeks in the last few weeks but with 80 degree days, who knows where they'll be next week.
From what I've seen, Lake Norman has more stripers but thay are generally smaller. Hickory and Rhodhiss both have bigger fish but they are harder to find and catch.
I've never fished Lookout Shoals so I can't really say about it. My advice is if you want to catch fish, your best bet is Lake Norman in Mountain Creek or one of the creeks above the 150 bridge.