Here is a red dot:
http://www.mountsplus.com/miva/merch...CH/EOT-551-A65
or
http://www.uws.com/AIMPOINT/M2.html
I have both the aimpoint and the Eotech.
Both are great, both allow for fast target aquisition, and allow for use in very limited light.
I have had fiber optics on some of my handguns. They are great, when there is available light. If you are in a low-light situation, they suck since they do not have an independent light source to power the sight.
The fiber optic may improve your speed on target a bit. (Assuming there is enough light to make it stand out). The red dot's are really fast. I almost feel like I'm cheating when I use them. They really come in to their own with moving targets, or when you are moving.
If you can look at some of these at a store, i would try that. Some of the red dots can be pretty pricey.