How do I install a ceiling fixture so I can then hang my Tiffany .

An electrician will need to add a box if needed, or do you mean something like this:
Westinghouse 70059 MODERN CANOPY KIT BRUSHED PEWTER General Light Fixture Part at eLightBulbs.com (http://www.elightbulbs.com/Westinghouse-70059-MODERN-CANOPY-KIT-BRUSHED-PEWTER-General-Light-Fixture-Part&source=GoogleBaseCSE?gclid=CMyZhMTuqq8CFQid7QodpTY uaw)