Pete,
The XS Big Dot on a revolver is a useful modification. I have 2 on my revolvers. The 1st is on my Model 38-2 and the 2nd was on my Model 65-5 3-inch.
They are well worth the expense of having them dovetailed into the barrel. The man who does this well is Karl Sokol of Chestnut Mountain Sports in West Rutland, VT.
One thing you'll have to think about is having the rear sight channel widened (with a ball cutter). Karl is your best resource for this. He's done many of them.
As others have said there's also value in retrofitting the original front sight with whatever.
If you want Tritium, try Tooltech in Michigan. They are the Trijicon sub-contractor (they did the front sights of the Police M92s of yore). They can put a Tritium vial in your front sight. I'm planning on having them do it on my Model 28-2.
Another resource is Scott Mulkerin of SDM. He can make a front sight and/or install a 14K gold bead on your existing front sight.
Lastly, there's Cylinder and Slide who can do whatever you desire. Their waiting list is measured in years, however.
Bottom Line: You can go from Mild to Wild with the front sight. I would think you want a perpetual, long-lasting front sight from which to stake you life on. If it were me, I'd have Karl do it. You won't regret it. Just my $.02
gtoppcop