I once had a Krown guy rust proof the bottom with non drip and the rest with drip proofing.
Gravity feeds. Notice the car rarely rusts up top? usually all of it occurs on the bottom edges. If you get the non drip you can always follow up as you mentioned with periodic drip proofing. You have to keep on it. EVen the krown guy told me this.. JUST A SUGGESTION....I'm not liable for my comment. (Grin)