I switched to DISH from DTV a few years ago.
Much happier.
You should be able to use your existing Wally. You might have to buy a new card to activate it.
I have a Hopper and a Joey at home and a 211Z (pre Wally) in the RV.
Not schlepping a rcvr back and forth is nice.
My concern/advice is is DISH going to want to start you in a new contract to get you new equipment in your house or not. If you donโt care about a Hopper, you might be able to buy another Wally and have them add an antenna and not have a contract.
Got some questions to ask.
My Kharma ran over my Dogma.