XXXXXX,
When using a 16"x8" wheel as little as 4" of backspacing(or 0mm offset) will typically clear the brakes of a GMT800(2000-2007) Silverado. However do to the significantly larger brakes that your truck has as compared to the brakes from the pre-88 trucks I am unaware of an off-the-shelf wheel that will fit properly. While a 1" spacer may be your only option in order to fit the wheels you have in mind on your truck, I do not feel that it is a "good" option. A spacer that large will require you to upgrade to longer wheel studs in order to maintain enough exposed threads to properly secure the wheel. In addition the extra 1" of width the spacer adds acts like a lever on the hub/bearing assembly and transmits extra load to the bearings, potentially leading to premature failure of the hub assembly.
I hope this explanation has shed some light on wheel fitment for your Silverado, if it has please hit the "ACCEPT" button.
Thanks, and Good Luck. Brad.
GM Certified Technician
ASE Certified Master Technician, GM Mark of Excellence Platinum Award Winner.