I know this is not what you asked about, but there is a straight-forward adaptation of "Heart of darkness" starring John Malkovich and Tim Roth. I think it was shot for TV, but I guess it would be worth a look.
Also, can anybody tell me if "Apocalypse now Redux" is closer to Conrad than the original? Nothing against the old version, really, but I am curious since it is difficult that ANR will make its way towards a theatrical release where I live.
But please, don't enumerate the differences between both cuts, because I have already read a lot about it.
By the way, all those interested can get an early draft of "Apocalypse now" at
www.movie-page.com "scripts" section. THAT one is quite close to Conrad, but I guess it was never shot as it is, though some parts of ANR are present, such as the French plantation episode.