For an excellent how-to guide on shellacking your handlebars, see Dan Goldenberg's instructions at http://www.mindspring.com/~d.g1/shellac.html
Over the Holidays, I used Bulls Eye Amber Shellac and yellow Tressostar to wrap and finish the bars on one of my Peugeots. During the course of a single weekend, I applied seven coats of shellac to achieve a near perfect match with the bike's honey-colored Brooks B17 Champion Special and Christophe leather wrapped toe-clips.
FYI, I painted a pair of black Velox bar ends with Humbrol modeling enamel (Antique Leather) and inserted them after wrapping the bars -- I shellacked them too! They match well and have held up great so far.
My next projects are a clear shellac/red tape combination for my blue Mercier 200 and a clear shellac/yellow tape combination for my purple Peugeot UO-8.
Good luck with your project!