I have gap gaurds on my 98 and they are definately worth it, my friend has them on his 99 Z71 and they definately make the truck look much cleaner. Id just buy them instead of trying to make them. As far as the steering, you shouldnt get more play from the spacer.

Also ill see if i can get some pics of my friends 99 with the body lift, the shop that did his suspension stuff did a real nice job of trimming and it looks really good, you can barely tell that they did anything different to it