Crossfire, thanks for the input. I changed up since my previous post and spent the bucks for a King Dome unit. I know a lot of people have issues with them, but we tried out the unit on our last trip just sitting it where we thought it would work best and running the wiring through the window for hookup. A couple of things came up for us. One is that in the morning when the ambient air temperature in the coach was not an issue (we didn't use the A/C that weekend - weather was great!) the receiver worked just fine, no problems at all. But once it warmed up during the day, we started to get some signal drops. At first I thought it was the dome dealing with sun reflection, but then I realized that the receiver was getting extremely hot sitting in the cabinet with the media switcher. I think there might be a thermal problem with that receiver as it works just fine sitting in our bedroom, but I think now that putting a receiver in that location might be a problem. I am going to try a different one next time. Second issue is finding a suitable 12v source in that cabinet for the dome to use. There were three pairs of wires coming in with one set going to a device that also had the TV power plugged into it. I think this might be the interrupter from the ignition switch to kill the tv. The second pair went to the 12 volt input on the video manager and the last pair was capped off. I tried to use that pair for the dome, but apparently there was no voltage (didn't have anything with me to test either). So, now I have to open up the backside of the TV area and the cabinet to see what is wired where and how. We also found that the video RCA jacks that are mounted at the back of the cabinet do not have very good connections. We could move the jack up and down killing the video to the tv, not a good sign.
Anyway, what I am trying to figure out now is making sure the holes I put in the roof are going to remain water tight. The roof to me is either fiberglass or plastic, certainly not rubber like my previous MH. So I believe that normal 100% silicone is the correct sealant, it appears to be used for everything else on the coach except the factory seals around the vents, etc. I am not sure what that is and I am not even sure you can purchase it in a tube form.
My concern is where the three cables will enter the coach and the underside of those cables going in is going to form a gentle bend that will be up in the air slightly. Filling that gap I think is going to be trouble.