I used a set of FATTIES 4-inch round mirrors with curved arms from Hagan Street Rods:
http://www.haganauto.com/category_s/197.htm
They have worked really well. Although I think the brand name is kinda dumb, the mirror surface is slightly convex which gives you a nice wide field of view, which I really need because my cab is only 3-window. Also, I think they have a sharp appearance and fit the natural look of the truck. They obviously aren't the stock mirrors but I don't think they jump out at you as obviously aftermarket either. Build-quality was top-shelf.