Dragging a bucket can be a real drag, even though I do it regularly. I can see where a bubbler would be a lot easier if you've got the room. With bull minnows, if you dunk them good every few minutes, then put the bucket back in the boat, they're fine. Shrimp are a whole different story.
I use an Engel bait cooler with a bubbler. I've used the cheaper styrofoam bait coolers, but the shrimp nor coolers last nearly as long. Frozen water bottle in the bucket will help cool water, thus raising oxygen levels.