By itself it's AK times two for double the cost. It's a sorcery but you can also build around it.
Any particular reason the colored mana requirement is so harsh? Seems like it would be fine at 2GU.
I'm decent at throwing effects together. Making sure they're reasonably costed.. well.. I'm not so strong in that area.
Edit: After thinking some more, I'm wondering about lowering the cost, having it only give yourself a poison counter (or 2), and then having you draw a card for every poison counter you have.... taking the blue out and making it green/black. Maybe a 1GB Sorcery.
Vision Quest

Sorcery
You get a poison counter.
Draw a card for each poison counter you have.