Your probably looking for something like this. It will keep your bait staitionary and off the floor. It has a snap for your sinker. If 5 ounces doesn't hold, go heavier.
https://www.causewaybaitandtackle.co..._c_347_11.html
I dont have any experience with baloon rigs.
I would think if you use them you would want to let them drift anyway.