Versatility. How to APC carry? All ideals welcome.

If your top lane/jungler is Wukong/Jarvan and Volibear is your support. It's safe to say your marksman should try to build AP. Of course Tristana, Ezreal and Kog'maw come to my mind.

I've ran into this problem a lot in ranked being that it's decided that I'm "adc" but or team is most ad. I don't want to lose a match simply cause the enemy team has freaking thornmail, you know.

Inevitably, I fail hard every time. So I was wondering, what's the correct way to build APC? Of course I know Lich Bane, Nashor's tooth, Rabadon and sorc shoes are essential, but I don't know what order to build them in. As for the last 2 items, I'm always thinking Morrelicon, void staff/liandry. This seems like the correct way to build and makes sense to me, but the early and mid phase is so slow against an AD champ that I normally get steamrolled.

Is this not smart building. I know how to build ADC no problem, but as aforementioned, losing a game over thornmail just sucks. Of course lifesteal counteracts that, but you get the gist.