Hold fire on that MarshalK - You CAN'T simply "split" a DBS cable like you can a regular TV cable. You'll need to get a 2x4 Multiswitch (both LNB outputs to the "2" side of the multiswitch, all tuners on the "4" side of the switch). Or, you could get a Dish SW44 or SW64 to accomplish the same thing.
Otherwise - I can't see any reason why the 721 shouldn't work fine with just a 119. As ScottG pointed out, we KNOW the 7-9 day guide is only available on the 110 satellite, yet the 501 also works just fine on 119 only.
Otherwise - I can't see any reason why the 721 shouldn't work fine with just a 119. As ScottG pointed out, we KNOW the 7-9 day guide is only available on the 110 satellite, yet the 501 also works just fine on 119 only.