The typical fiber optic sights are pretty clunky and ugly. What I'm using now is a TOW front blade sight (suitably filed down) and with a short (~ 1/2") piece of small diameter fiber optic rod glued to the top. I got a bunch of the fiber optic rod of different diameters and colors from Ebay (several vendors offer different things). I've got orange on it at the moment, but will probably put green on it. I use a bit of GorillaWeld to glue it on, and it even works on the nickel blade (though I do treat it with a bit of soldering acid just before I glue it).
The only real trick if you go in that direction is that putting the fiber optic on top of the blade to make it a visible "bead" of course increases the height. So it takes a bit of painful trial and error to get the blade filed down to the right height so when you add the fiber optic it works out right for you. But, for me at least, it's well worth the effort.