depends on how much you're willing to pay for paint.
for example, if i were to get my kit painted the stock silver, i'd have them order the 1D0 paint from (i think) DuPont themselves. that is the factory paint used. but there are also instances where the paint matches are perfect/nearly perfect.
if the kit is an authentic one with perfect fitment, you should install it yourself. that way there wouldnt be any need to do body work, unless the kit has bad fitment.