An alternative thought:
I have 2 C band Buds on separate Diseqc movers. I have never tried to control both with only one receiver as you plan to do. BUT... I have found my systems work more reliably with the Diseqc boxes in stand-alone mode. We change Sats with the Diseqc remotes, the receivers do not have control.
Every receiver I have owned has had some sort of problems when in 'control'. Missing/added counts, runaways, etc. I'm sure some combination of: better grounding, motor cable, better Diseqc boxes, new actuators might resolve all that. But it works just fine like I have it now without the added expense.
Sometimes we forget where a particular channel is located... this way, we can view the channels on a Sat without the dish automatically motoring there.
It also prevents surfing 'Favorite' channels and running the dishes back and forth dozens of times. We now tend to check everything on one Sat before motoring to another Sat. Much less wear and tear that way.
Anyway, that's just what works best here. I have no desire to let the receivers have motor control again.