You'll hit the bump stops regularly if you leave em. I just took mine out, almost never contacts the frame, except when loaded.
As far as shocks go, I'm running the KYB Gas-A-Just shocks all the way around, and let me tell you, the improvement over the crappy Toxic shocks was massive! It actually rides like stock again. And I took measurements, the KYBs listed for a stock application, are the right lengths for a 4/5 on the front, not sure about the back, since I have a different shock setup. But heck, you could just get KYBs for the Nissan on the rear.
And one other side note, Alan, that pic you posted ain't a bolt on notch, this is.