i have the DISH 722 DVR and pull it from the house to the RV whenever we travel. I stick it under the TV in the cabinet while traveling to keep it from running all over the place. You could just buy a foam filled box at Fry's or some other electronics store and put it in the box. I do the two DVD screens for the back of the King Ranch that way.
For hook-up, I have a King Dome and there are two lines coming in from it. (I just recently pulled a connector off and am using only one feed.) I have the 3400RL.
On the back of the receiver run cable into Sat I and Sat 2 and run the feed in. On the wall in cabinet ther are three RF connectors. One is a jumper. The other is the feed from the outside. (You should be able to use that also, but not sure) If you use the outside line in, you will have to use the switching mechanism provided by DISH (See: http://www.montanaowners.com/forums/...3&SearchTerms=
From the back of the DVR, hook the output to the top jumper. leave the bottom one hanging (or free) Take both remotes with you. (Also the RF antenna provided by dish hooks to the back of the Dvr.
Enjoy two televisions both viewing different channels.