If you're purely looking for enhanced visibility, then you might consider just getting some 4-inch-wide 3M Scotchlite in the sew-on variety, stitching a couple sections together, terminating them with Velcro, and they should utterly dominate the Illuminite. Or if you actually want legwarmers for their own sake, maybe get some standard legwarmers and iron on some 3M Scotchlite.

Ten feet of the 4-inch sew-on stuff is $16, and ten feet of the 3-inch iron-on is $19: http://www.identi-tape.com/refl-fabric-gateway.html For some pics of how it looks, see this thread: http://www.bikeforums.net/showthread.php?p=7459700