An update for everyone here: the install at the ranch property was today, and I'm happy to report everything went great. The installer was local to the area, was well aware there are a number of similar ranch type properties and had no issues with the setup. We did make a change a couple of days ago and opted for 1 Genie DVR in their living room, a client for the master bedroom and a 2nd client for a kitchen (currently under remodel). The "fourth room" where the HD DVR was to go in the guest house, we went one step further: rather than the family having to purchase a brand new HD DVR for that building, I actually owned an extra HR-24 that I wasn't really using, and he simply transferred it over from my account to theirs. Win win!!
The only thing we could not configure was internet access - for both the main house and the guest house. There's internet in both, but the receivers are not picking it up from the routers, wired or wireless. No idea whats up with that, the internet otherwise works perfectly fine.
Thanks to all for your encouragement & suggestions on how to proceed - the family is very happy and so am I!