D500 preferably with I-shaped adapter, a DP dual LNB, and some RG6 cable in a length adequate to go from the D500 to the 1000.2. Normal max length of RG6 for DP equipment is 200', but I have no idea how much less this might be hanging off a 1000.2. Maybe the total length (?) should be less than 200'?
Caveat 1: 77 is very close to 72, so you have the potential for interference from 72 on a D500. It has been done, but best practice is a bigger dish (the 1000.4) which has adequate resolving power to separate the two.
Caveat 2: If you have the 1000.2 fed to a DPP44, then you would run your wing dish to the DPP44 and not to the 1000.2.