LS4 Performance - 19" tire size thoughts

Im looking to run 285/35-19's in front and 235/45-19's in back on my '06 Impala...any thoughts? I really would like to run as big of a tire as possible up front.

If i had to hazard a guess id say they probably wont fit. Gxps are designed for wider tires up front and we can only fit 275/40' s

This is assuming of course you can find a rim wide enough in Our bolt pattern.

I'm having custom forged wheels made to whatever specs I want so that's not an issue. The 285/35-19 is the same height as the 275/40-18, just wider obviously, it's the size I really want to run because I think 20s are too big for the car, looks too ghetorific, I want sporty. My other option os a 255/40-19, but Since I will be able to have the tire as close to the strut as possible with the right wheel offset, I might only have to roll the fenders a tad to fit the 285's. Has anyone done that? Or am I dreaming?

I'm just sick of not being able to launch and all the stupid torque steer, and front end plow. But I'm not getting a new car, so I want to make the best out of this one. What's the biggest Tire people are running on the street?