I have the Steeda 4130 Chrome Alloy ones. There are really nice. They SUCK to install!!!!
Here is a real time savor. You can punch and drill the holes or thread them. If you thread them, the install is simple...no hand aerobics and bleeding nuckles. You see, if you use the bolts, they are quit difficult to instal because of the comments others have already made. The instructions say you can put them on either way. To thread the holes, you need the correct tool, but it's worth it.
Another option is to have them installed when you put on new springs.