Lots of people use just one stabilizer.. however, at their cost.. two is a good choice. The brackets, and both bars will be less than 30 bucks.
Yes.. you can put a ball thru a hole on the 11 hole drawbar.. however you will need some sort of drawbar lock to keep the drawbar from rotating. This can be anything from an aframe from the toplink to the 11 hole drawbar to keep the bar down, and fixed.. or it can be a simple device which merely keep sthe bar from rotating. There are numerous comercial and home brew designs available. I welded one up from scrap metal.. took 15 minutes.. etc. and bolts on real quick. This happens to be on my NAA, which is the next model up from the 8n.
Soundguy