Aloha Brandon,
I've still yet to find the perfect GT jerkbait, and most of the tuna jerkbaits have poor action. My favorite one for heavy whitewash conditions right now is the largest Rapala X-Rap; obviously rigged with upgraded hooks/rings. Biggest one i've taken on it so far is about 22kg sight casting to a fish coming out of a small surf break, and the wiring held up fine. A bigger fish would ruin it handily though!
Much like you guys found on your trip, i too feel that i get much better reactions to smaller sinking lures in shallow whitewash. And i definitely think that an all black color lure gets more action when the surf gets real big and nasty; probably the best contrast amongst the washing machine.