KM used to make all brass stuff until about 3 years ago. In Egypt El Ashrey and Shisha King still make all brass stuff but the don't export those.
I've a bunch of all brass Syrians (J & R, Furrat, Arabica Sous and a few others) and I think that the 4 smoke inlet stems are the way to go. Beyond that I like the easy cleaning of the multi-part cast stem types but the cast & sleeved are very good too so it comes to preference. *******'s Syrians look great but I'm only interest in getting rigs between 32" and 36" at this point.