As awesome as Tezzeret is, this deck wants to win on T4, I think the spot is better left to more draw spells, also, Thought Scour would be better replaced by something that digs more, like Serum Visions or Sleight of Hand. While it can trigger the combo, there are plenty of triggers in this deck that make it redundant.

People have been suggesting Taigam's Scheming for my list, but I'm not sure, maybe you might want to try it out though.

Thanks! Taigam's Scheming is a good one. Thought Scour's main purpose is actually to trigger the loop, and it often winds up being the thing that does, so I don't think I should take it out... I'm not so sure I need much digging though, it finds what it needs reliably. I'll be experimenting though.