There are reducing rings that allow you to use a 1" fork in a 1 1/8" head tube but there's little point; a 1 1/8" fork is stiffer where it matters. Most 1 1/8" forks are threadless and most 1" forks are threaded, just to throw in an extra complication.
Quill stems look nice, and most of my bikes have them, but a threadless setup is technically much better and you can really feel the extra stiffness. A quill stem is only attached at its very bottom and moves a lot during riding. You can tell this from the way a freshly fitted quill stem pumps grease out of the headset top nut!