I don't know if the SPUR will work on the AT. It does on the AT-84s, but don't know about the Sphinxes. (I suspect they will, but I sure wouldn't buy one assuming that it does...) The SPUR hammer can BITE. You may end up with a pretty gun that hurts you when you shoot.
I'd argue that adjustable night sights are overkill. Just get night sights. For home defense they make sense, but for range work they're not particularly useful.
(Unless you're playing around with a lot of different loads, or handloading yourself, adjustable sights are more LOOKS than FUNCTION. Most new shooters go that route when they first start shooting, but eventually revert to more practical sights.
Once you find a load you like, you'll probably never adjust them again.
Check with Arizona Response Systems about refinishing the slide. They do a ROGUARD-like finish that is very durable and attractive.
www.arizonaresponsesystems.com Look for the photo gallery -- I think its under the FINISHES tab. That finish will keep it looking stock but it will actually be a better finish.
(Several of my friends have had guns done in Metacol III and its a very durable "Slick" finish.)
If you've just got to have adjustable sights, check CDNN from time to time. They had adjustable sights for the SPHINX a while back. (I did NOT get them for either of my Sphinxes.)