Early game, AS boots/Doran's/Vamp Scepter, then BF Sword into Bloodthirster, then either a Phantom Dancer or Static Shiv, then IE. And then depending on how the game is going, the other things you mentioned.
E first, W second. E is really useful all around. A lot of damage, good for farming, and a slow. Max Q last because it can be somewhat easily dodged, it has to charge up and it doesn't gain as much per rank, so really you only need one point in it. I tend to use Q uncharged to quickly proc the W stacks on someone.