I need to know what kind of lnbf's you have, (IE legacy, dishpro, dishpro plus, single, dual, twin, quad ) knowing this will help.
If you have dishpro single, dual, twin, and quad then you would only need a total of two lines coming from the dish 500 ( 119, 110 ) to the dpp44 and one line from your dish 300 (61.5). With the quad you have to make sure that the coax from port one on the lnbf goes to port one on the switch and port two to port two and the 61.5 coax goes to port three. If you have legacy lnbfs I would recommend upgrading the dish 500 to a dishpro plus twin and a dishpro dual lnbf on the 61.5, run a single coax from the 61.5 to the single port on the dishpro plus twin and then you run two coax lines from the dpp twin into your house, one line goes to one 322 and the other to the second 322. Your 322's if new will come with dishpro seperators that will need to go on the end of the coax run to mirror the signal. All you have to do at this point is run the second tuner output to your remote tv.