Well, I'm new to lights so I haven't checked out all possible sources. I know that American Shooter's Supply (a gun store, you may have guessed) definitely carries them. Go approx. 2 miles West of Las Vegas Blvd on Spring Mountain Rd. (Spring Mountain Rd is on the N. side of Treasure Island) to Arville. Go North on Arville just a couple hundred feet and turn right into the parking lot. Be careful turning into that parking lot. It is very congested with traffic at times and people may back into you.
I was at the Bass Pro Shop (a.k.a.) Outdoor World and did not see any SF's. However, I was looking on the racks and they may have had them in glass cases somewhere. I was in a hurry and didn't ask. They had Streamlights and Princeton Tec's mostly.
If I have some time, I will call around and try to find some other sources but if you are staying on the Strip, A.S.S. is probably the closest.
There is another place just a little further up Spring Mountain that may have SF. Maybe a quarter mile passed Arville. Watch on the S. side of the street. When you see the dive shop, slow down and watch for The Survival Store. The guy carries an odd assortment of stuff. Some interesting guns for sure. I haven't been there for years because he is more or less open when he feels like it, maybe 3 or 4 days a week and his hours are weird too. Maybe like noon to 4 or 5pm. Every time I try to go there he is closed and I get ticked off. This happened just a few weeks ago...two days in a row! I swore that I would never go there again.