problem with decals is that paint would last ages longer. You will end up having to pull the decals after some years in the sun and getting custom ones to match down the road would be pricey.
Even if they are painted on striping, you could change them down the road as well, but if I were you and liked the look. I would pay out now to get a nice pin-striping done than have to deal with the car as the decals age.
