Coilover ride quality?

[We Gone]

Question for you coil Over guys regarding spring rates? Been doing searches for a few days and found no good answer.

Been considering going to them so I can lower one to one and a half inches (lose the 4x4 look). I have lowered C4's in the past with the long bolt rear and cut rubbers front, while it looked great I did not like the effect on the ride and would not do this to my ZR-1. I see most use 425/275. Does lowering change this rate? if so would I need to go with a lower spring rate?
I do not want to lose the ride I have now would like a rate that will maintain the stock ride or no stiffer than a 96 Z51 (have a 96 LT4/Z51 and its not to bad at all) when ride control is set to performance. car will only be used for lots of road trips. tell me your thoughts on how the ride changed if any and what rates you went with. And yes I'm getting to old to bounce my kidneys all day ..LOL

Thanks Steve