After some experimenting, I opted for the superbriteled.com 30LED: Red/narrow beam. About $9/ea. My C/S utilizes 6 tail lite bulbs + the 2 turnsignal bulbs (get the amber for these). My concern is the extra current draw thru the headlite & turn signal switches. LED's solve that worry: brighter, less current load. I'm not familiar with the other suppliers' parts, but they seem more expensive.
1968's: Best of the Best:
1968 GT/CS J Code