I have had cheap old MTB's with SIS 5spd but nothing of good quality, they did have 5 speed uniglide cassettes as we still have one in stock at the shop. I haven't seen a SIS system for a road bike, but I would think a 6 speed shifter would work with a 5 speed with a dead shift. If I was going to go through the trouble to make it index I would go with 6 or 7spd. I know there are 600EX SIS derailleurs for the 6spd on fleabay and would think it would work with 7 as long as you have the shifters.
Glenn
EDIT- boy I didn't realize how long it takes me to type until now, BG was the last post when I started lol.
Last edited by Glennfordx4; 05-17-11 at 09:53 AM.