Put them all on.
I had the same dilemma as I didn't like the rears, but they look better in the flesh fitted than in a picture.
Heres one for ya... I thought about adapting a set of fronts and putting them in front of the rear tyres too. I photoshopped it and it did look ok. The plastic is plyable enough to bend as well, only thing is I'd need to drill a small hole in the body work to match up with the holes in the splash guards....In the end I couldn't be bothered