Well can't comment on your preference, as you like
painted door handles look very cheap, i've seen them on glis and ativ's, chrome gives your car a peculiar glitter and shine... looks fantastic on black... just keep it polished and shining
I know people who buy chrome covers for their cars, you are the first case I came across who wants to downgrade to painted door handles...
if you want to do it anyways, get them painted, ask the painter to use a good primer so that the paint stays on properly, it wont cost you alot... anything between 3 to 5 thousand, however, i would still suggest not to mess with it..