The only one that I am aware of that is of any quality are the grillcraft grills, and even they are a sort of clip-on.

I want to replace the upper and lower stock grills with something nicer, pref billet. ANY and all links are appreciated!

Billet grilles are available here: http://www.mrgrille.com/ , but Im not sure if they are clip on or full replacement pieces.

They are clip ons that go over your stock grill. I could have sworn that I have seen a post earlier where someone installed a non grillcraft complete grill. Oh well...

Another grille company is T-Rex Billet Grilles (http://www.trexbillet.com), but it is also a bolt on. Not sure if there is anyone who makes a replacement for it. I believe there is ways you can jimmy it to work as a replacement.