Although you would technically be invalidating your warranty by having a remap it's extremely unlikely that Fiat would disocver that you'd remapped it.it doesn't affect your warrenty in most cases
I've seen pictures of a few body kits online and none of them have really jumped out and grabbed my attention.i do like wide arch kits but not many about as far as i know
another 10, maybe 15hp, probably with induction too.What kind of extra power would you get then if you have the 1.4 sporting re-mapped ??