QBP stocks the CDS and the Passage. Both are steel, 'triple sealed' (lower cup, upper cone, locknut seals) and are an upgrade from campagnolo's vintage headsets. The CDS has a stack height of 33.4 and the Passage has a stack of 30.3. The CDS has the rounded profile that King headsets have made so popular. The Passage is more low profile and has more right angles in the lower cup and upper adjusting cone.
Wilson Bike Sales stocks the Levin steel (stack height of 38.2mm) and Levin Alloy 1500 (stack height of 42.7mm). Both are suitable replacements for vintage Campagnolo headsets in terms of asthetics, fit and function. From 10 feet away it would be hard to tell the difference between a Campy or Tange.
For you vintage BMX'ers, Wilson also carries the Pro 1" BMX headset, but I don't want to get too offf topic, or be too gauche......
There may be other distributors, but these are the ones I know about.
Tom Martin
Oakland CA