BMR makes the cheapest differential bushings. It is a three hour job to change these bushings. A BMR franchisee may have a tool to speed this up. I haven't changed mine because of labor cost. Do subframe bushings at the same time because subframe removal is probably required unless there is some special tool involved.
I did install the Pedder EP1200 subframe insert bushings and they did tighten things up. You can feel the expansion filler bumps a little more on a concrete road but it is no worse than my Nissan truck which rides pretty nice. I don't notice it on the Interstate or asphalt. These were $255.00 and pretty easy to put in. They fit above and below stock subframe bushings. I think this is worthwhile.
The EP1201 is a replacement bushing set for $462 and they even have an EP 1201HD set for $595.00. Both require removal of stock bushings. This is labor intensive. I think they make a tool that helps. These are recommended over 450 rwhp I believe. I am sure these will make the ride harsher.
I installed the BMR toe rods because it was easy but didn't really notice a difference in launch. The Spohn toe rods are adustable for toe adjustment on alignment. BMR makes an adjustable and non-adjustable toe rod.
After market lower control arms are coming out now. They may help more than upper toe rods. Stock control arms look pretty strong though.
I really don't have an issue with wheel hop with the 17" MT's. The Nitto drag radials will help control wheel hop probably more than anything else after the Trailing Arms. You can run them between 16 and 20 PSI to stop wheel hop. They will also improve 60 ft. more than any other add on and save the expensive stock street tire.
The 18"Z06 replica rims are pretty cheap and fit well. You can then run any brand drag radial. I can run a 1" shorter tire in front than back with no ABS issues. I assume same is true visa versa. Smaller the front tire the more weight savings where it counts. ABS keeps getting more sophisticated and you may even be able to get away with bigger difference in tire size.
It looked like the current, just shipped, GM High Tech Magazine test of Nitto NTO5R's ran a 18x9 front Z06 rim on the back with the NTO5R and stock rim and tire on front. This is probably a 2" tire height difference. I have been told the rear Z06 18x10.5 rim will also work but I would think the backspacing is awfully close to the back of the wheel well. (small spacer?)