Tritium sights

[PlaneEngnr]

I'd like to get a tritium sight for my revolver (GP100, adj sights), but I'm only really interested in getting a front sight.

Can anyone recommend a place that sells just the fronts?

I've checked the regular places Midway and Brownells, but they just have the sets, at least that I've found.

 

[GTSteve03]

XS sights sells a Big Dot and a regular dot for the GP100, I do believe.