As an alternative to a red dot?

http://www.midwayusa.com/product/122784/xs-front-sight-post-ar-15-steel-matte-tritium-standard-dot

I had one years ago they have improved over time. This type would be fine at night at relatively close range but not ideal at longer distances. You need to work with it to know what you are getting because one typically sights with the top edge of the front sight either held splitting the center of the target or as pumpkin on a post held below the target. With a illuminated front sight on a pistol the impact should be center of the illumination dot which is a different hold but so long as you know how you are going to hold the front sight you should be fine.