Having automated shades installed wound up being an enormous pain in the backside for me, so I thought I'd share my final solution with everyone. Maybe it will help someone else...
If I were to do it all again, I'd definitely have gone with QMotion, which is apparently much easier to integrate. My dealer sells qmotion, but for a variety of reasons (largely because they didn't have as many fabric choices and they hadn't done many motorized blind installs), I decided to go with a local decorator with a budget blinds contract.
My house was hardwired for low voltage with Cat5/6 cable to every window that I would potentially have automated. This was the first issue, since many motorized shades (including the somfy motors I wound up with) use a simple two wire (positive/negative) cable, which I believe is 16 AWG. Cat5 cable has 8 wires, which are 24 AWG. After many phone calls, finally figured out that if you combine 4 of the wires together, you get the equivalent of 18 AWG, which was close enough to make it work. I twisted the solids together and the stripes together, to give me a positive and negative wire. My house is about 4000 sq ft across 2 floors, and this wiring setup is able to carry enough current to make the motors work properly. I'm not sure exactly how long the run is, but it goes from the basement on one side of the house to the main level clear across the house. I believe Qmotion avoids this hassle, since it natively works off of Cat5 cabling.
All of the wiring terminates in the home theater / automation control room in my basement, and I hooked all of the wires into this 10-Motor 24V DC x 20 Amp Power Panel. Somfy also makes a version of it (also sold on this website), but this is nearly the exact same thing for less money.
As for control of Somfy Motors with C4, the best way is apparently through Somfy myLink. To make it all work, you first program the shades using any Somfy remote. Once they're programmed with the remote, you download the myLink smartphone app and essentially copy the programming into the app (you cannot setup the shades or adjust the limits with the app). Once the myLink app is setup and working, I gave my dealer a code from the app and he was able to quickly program the shades into C4 with the myLink driver. It was fast and easy enough for him that he didn't even charge me for it. You can also use the myLink app on your phone for control of the shades, but the app sucks. I only purchased one of the myLink devices (which converts the wifi commands into the Somfy RTS signals), and it covers my 2500 sq ft main level without issue.
The only limitation I've found with the Somfy motors and myLink is that they will report to C4 whether they're open or closed, but not anything in between. So, you can only set them to full open, full closed, or one other intermediate setting that you define when you initially program the shades.