Terk is over priced. If you can find their stuff for comparable prices to other companies, they are fine. But don't pay more. The only switches that really stand out and you MIGHT want to pay more for are made by Spaun. The BMS-34 is not adequate for an HD setup with an oval dish. You need a 4 or 5 input multiswitch.

You cannot split the sat feed except with an appropriate multiswitch. This can be wherever you want it, closer to the dish or closer to your receiver, but you will need all 4 lines from the dish run all the way to the multiswitch to get the HD channels from DirecTV.

However, if the DVR is the only sat box in the house, you don't need a switch at all. Then you just need 2 lines from the dish all the way to the DVR. Since the dish has 4 outputs, you can run up to 4 receivers or 2 DVRs or whatever combination without a multiswitch.