I don't own a sportster, but if it has a hole drilled and tapped for a front sight. You could probably give Williams fire sights a try.
You could go with Williams Sights, or also with Marble's. Also I found that the orange fiber optic Marbles is much brighter than the red Williams. Both make fiber optic front post/blades in 1/16" diam., but also 3/32" diam too,
if like me you need the extra help to see em well!
To get a good fit for the front sight and if cost isn't huge concern, choose a .250" wide base that will attach to that screw hole or it can soldered on too).
Finding a perfect-fit one-piece fron sight would be sheer luck! Most likely you'll need to two parts to make the best front sight if you use something else besides H&R's stock front sight.
Its recommened (as ideal) that .250" wide base needs to be half as tall as the whole front sight's total height, with the second half of the height made up by the actual height of the .250W" 3/8"- dovetail front blade. (check out MidwayUSA,com's site for the sight parts, using lots of patience as you wade through everything!)
