So after years of looking I got a great deal on this spiffy '86 Schwinn Peloton with a threaded fork and I'd like to put a white, non-quill/non-threaded white stem on her.

Since I got the frame for a song, cheap is not a priority. However, it's a Sherman tank of a frame, so a lightweight option would be appreciated.

Am I stuck getting a quill adaptor like this?:


If so, what's the lightest/stiffest option available? If not, what other lightweight/stiff options are there?
Mille grazzi and safe riding!