check year one's site (I think it is www.yearone.com) I beleive they have the door panels as well as Poston's or Kirbans as for the door handles I don't think anyone does. When I first read your post I thought you wanted custom Hot Rod type, if so check out Phipps Products, nice stuff. You could also grab a Street Rodder mag and browse through the advertisers, sure to find alot.
Otherwise grab something to pop the rivets off and head to the junkyard, sure to find something nice.