who_else,
I bought some Williams Fire Sights back in December and I' m very happy with them. They are milled not stamped of aicraft grade aluminum. The fiber optics in the rear sight are actually set inside the metal. The rear sight is also dovetailed to provide for a very solid mount and can be adjusated for both windage and elevation. They come now as a universal mount to fit all rib widths. The sights attach to the rib via a clamp on each side which is secured by two allen screws on each side. I looked around at the differn' t sights and these to looked to be the best built and most secure. I got mine from Natchez Shooting Supply on sale for $24.99 which you can' t beat!

They give really good light in both sun and shade.
http://www.natchezss.com
http://www.williamsgunsight.com