I'm guessing, but there's probably very little difference between the 211k and 211z. The "z" model is probably a mild update with a new feature or two. I would compare the two, but chances are that the 211z will be the better receiver.
Since you're using a dome, there is only one LNB. That means that one receiver will control where the antenna points after running "check dish". To get to "check dish", press menu-6-1-1 on your remote and select it on the screen. That will setup the antenna to switch satellites based on the channel selected. The second receiver will have to watch channels on the same satellite the first receiver is tuned to.
For example, most HD programming is on satellite 129. Locals tend to be on 110. Satellite 119 has a mix. Dish has two sets of satellites for east and west. Since you're in NC, you're probably going to be working with the eastern arc. The ones I mentioned are in the western arc.
If the need to watch channels on the same satellite gets to be a problem, you can always run a second antenna (carryout, Tailgater, tripod mount, etc) to feed the second receiver.
2019 Dynamax Isata3 24FW