upgrade old cable boxes

Have a couple old RNG150 boxes from 2009.  Recently bought a new Samsung 65-inch tv.  Wanted to get another cable box for that.  Y'all sent some SD box from 2011.  Incredibly insulting.  Looking to trade in all 3 old boxes/remotes for 3 of your newest, most technologically advanced cable boxes/remotes to watch 4K/UHD programming.   Looks like Arris XG1v4 or Arris Xi6 (unless I'm mistaken).

Apparently I'm also being charged $15/month for not returning an old modem that we recently upgraded from.  We now have your all in one modem/router combo.

Old stuff for new stuff:  So yeah, let's make this happen.  Thanks.