really half-*** response here but the guys out here that drift one have some sort of knuckle mod so that they can get more lock out of the steering. Otherwise the car has more tendency to rotate around. Then again, Tiff Needel didn't seem to have any troubles drifting a stock one in his review.
For tires I would certainly not stay with 19's in the rear, as they will break the bank in a hurry. I'd also run something narrower than the 325's, something closer to a square setup.
That's the best I can respond with my very limited knowledge. There's a lot more to drifting than meets the eye. Most all of it is driver.