Hello. You should forget about the rf part of it. Go IR and use the program called Girder. I have a remote that has a qwerty layout keyboard inside it (flips open to reveal). Here are two pictures of it


And with Girder you can program each button to do whatever you want. And I do mean WHATEVER! It is so flexible and powerful that you honestly wont need anything else. You will need any remote and an IR usb receiver along with the program.
The main reason I am reponding here is that I have the same static problem as you. Only when I turn the volume up and only with the bass hits. I get some lines and that flicker or roll in the screen. I just put in an XAV-7W. I used to have an Audiovox 5.6" in the dash and I was running it off the computers PSU because the static from the cars power was insane. The car battery powered the screen fine until I started the engine and the line went from 12 volts to like 14+ which made the screen go nuts and become unviewable. So I just decided to power it from the computer. But now I can't do that because it's a whole head unit and not just a little screen. Plus I like having the HU's remote line start up and shutdown the computer. So - did you ever find a fix to your static problem? I was thinking that the CAP might do the trick, but before I try I wanted to get some feedback from you. Your last post was ages ago and I wonder if you'll even see this...