dude its real cars not model cars it cost to go custom...
If you run air you'll get it sitting on the ground, but be prepared to spend about 3k if not more if you have no experience in regards to install .you have other options in the way of lowering springs, I have no input on cutting a lowering spring.
I'm going for the VIP look, low and flush to get there this has been my process:
I'm working to get the LS fitted with a new body kit (off the shelf cut up and custom),his will give me a stock suspension height with the kit's "lower bumpers, side skirt sitting)
from there the right height will be figured out (its going to be daily driven kitted slammed and flush so what spring offers the lowest yet capable of driving with out destroying the kit)
then the best possible combo of rims and offset and stretch. I have wheels in mind and by the looks of it after the lowering is done and they are fitted i'm going to have to radius the fenders
Not trying to high jack your thread, I'm just trying to show you if your going to go above just lowering with rims, its a process, the longer you take to measure, research and plan the better the execution will be..
Go for perfect, don't settle for the norm because it easy.