We put on the L&M lowering spring on my wifes bike and it dropped the rear a few inches. She only has a solo seat so she doesn't have to worry about riding with two people. She has not had any issues with bottoming out. We did have to softenen the spring setting. This spring took the dealer two hours to install.
I put the PCS lowering links on my bike and got a similar effect and I was able to do it myself in less than an hour.
Any other questions just ask.