As Jeff mentioned, the learning curve on adjusting a 3pt plow is very steep.
Even in the video you can see that he doesn't quite have his plowed centered behind the tractor. He had to consistently turn his front tires a bit to the left to stay where he wanted he in the furrow.
There are lengthy threads here on TBN concerning this topic. If you get a plow purchased and have troubles getting it to work properly either search those threads or start a new one. Lots of opinions concerning proper plowing techniques!!!!
In regards to your field, is it flat and level?? If not you are going to create a disaster by simply plowing and discing it. You'll only grow two things, weeds and ditches.