If you are looking for plug and play.....put your key in the ignition and drive the car...don't mod it.
I'm gonna let you think for a little while as to whether or not wheel offset and camber have an effect on the speedo.
But I will give you a hint about lowering the car...always get an alignment whenever you change anything in the suspension.
I think it would do you some good also to spend a few weeks reading every stinking thread on this forum from front to back, including all the threads that talk about everything that you are asking.....and then see if you still have questions. Use the SEARCH function and READ.