The Pro-kit or Steeda sports will make it handle better. (I have ultralites but if I were to do it over again I might have gotten sports) When you lower the car that much it makes it so you hit max camber before hitting full load and start heading back towards positive camber. Your static camber will be higher but it will be lower when you need more camber under load. Thats why Steeda made the x5 ball joints and/or control arm relocation kit.

The 2 inch drop in the back changes the angle of the control arms more than other springs and will cause loss of traction unless you get relocation brackets.

We really do change a lot when we lower these cars. The good news is that there are fairly inexpensive parts that will correct the geometry after lowering.