For people working with an HD format:
They could use the Apple pro res 422 if they file was worked on a mac, but this format is not supported on PCs, so if they someone with a PC wants to open the file, it wouldn't be simple, they will have to convert it, therefore, maybe loss of quality.
So another best solution would be a more universal codec, that would be the H.264, which he recommends for less worries.
Now in my case, originally, I wasn't working on an HD format. My video's specs are 1024 x 576, which is not HD.
But after deciding with Jonathan to have a split screen (on the same monitor, the edited clips and the looping edited version of the live), I will have to place both clips in an HD format: 1920x1080 since this format fits better 2 clips than the format I am using.
I will have to render my files in Final Cut Pro, then take both rendered clips to After Effects which, unlike Final Cut Pro, doesn't resize the clip once I change the file size, and do the split screen operation from After Effects, and again render to H.264.
The file's extension will be .mov (which the WD Media player accepts in my case).
We should have the work backed up on a DVD as well for the show, just in case.