Hi
The highest quality (according to Panasonic) is 1080P50 (or 60) I'm in PAL land. so I'll talk PAL for now. The problem with this is that Log and Transfer won't recognise the non standard frame rate, you will have to convert to Pro Res before importing into FCP. You then have the choice of leaving the frame rate at the original or changing to 25 fps during conversion, and a further choice of editing 50fps in a 25fps timeline or in a 50fps timeline Converting to 25 fps later.
Of course the other option is to shoot at a slightly lower quality at 25fps but I think that camera only has the one progressive setting which is the one we've just talked about, I believe all the others are interlaced although 1080 is one of them.
DM